(Topic ID: 232762)

First time board repair (transistor)

By tp

5 years ago


Topic Heartbeat

Topic Stats

  • 43 posts
  • 15 Pinsiders participating
  • Latest reply 5 years ago by tp
  • Topic is favorited by 6 Pinsiders

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#1 5 years ago

So my Metallica pro has been down for a while. With the new code and all it's time to get it back up and running. I got a new soldering iron that was recommended here for Christmas so no more excuses.
I'm looking for good advice so please feel free to give it. I'm at the stage where I'm gonna order the parts.
Heres what's wrong.
Left flipper stuck up when game powered on til it blows fuse or powered off.
Left back panel flashers stuck on.
I've concluded that transistor 15 and 21 control these and need to be replaced. Should I replace anything else while making this repair?
Please feel free to point out any tips and useful information as this will be my first attempt at this.
Thanks tp

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#2 5 years ago

I don't going in and start changing things until I know it's an issue. Did you check the transistors with a DMM set to diode setting to test the transistor?

Also, to get the transistor out you are going to need a solder sucker or desoldering station.

#3 5 years ago

Practice on a old vcr or some other junk.

It's going to take you 30 minutes of practice before you can do was properly.

#4 5 years ago

I just got this gizmo based on some other postings on Pinside. Seriously impressed. Checks transistors and FET's (and a lot of other stuff too). Checked about 3 transistors in less time than it took to type this. Don't even have to worry about connecting wire to the correct pin. Just hook it up, press test...and it figures it all out.

As Schud eluded, take the part out to test.

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#5 5 years ago

What tool do you have for desoldering?

Quoted from mbwalker:

I just got this gizmo based on some other postings on Pinside. Seriously impressed. Checks transistors and FET's (and a lot of other stuff too). Checked about 3 transistors in less time than it took to type this. Don't even have to worry about connecting wire to the correct pin. Just hook it up, press test...and it figures it all out.
As Schud eluded, take the part out to test.
[quoted image]

If you can get the part out you've already done the hard bits. Might as well put a new part in at that point.

#6 5 years ago
Quoted from vid1900:

Practice on a old vcr or some other junk.
It's going to take you 30 minutes of practice before you can do was properly.

I have a board from a time machine I can practice on. I'm assuming I'd apply heat to backside and grasp transistor with needle nose and pull out? Correct way > assume

#7 5 years ago
Quoted from schudel5:

I don't going in and start changing things until I know it's an issue. Did you check the transistors with a DMM set to diode setting to test the transistor?
Also, to get the transistor out you are going to need a solder sucker or desoldering station.

Never tested the transistor as I dont have the tool shown above but can order it.
Pretty sure it's the transistor as when i discussed flasher stuck on with chaz(stern)he seemed to think that was the issue. As for flipper all signs point to bad transistor but again haven't tested.
I dont have a solder sucker guess I need to get one. I haven't removed any transistor as of this postung.

#8 5 years ago
Quoted from tp:

I have a board from a time machine I can practice on. I'm assuming I'd apply heat to backside and grasp transistor with needle nose and pull out? Correct way > assume

You want to remove the old solder, then the part should just fall off the board. Doing it the way you suggest could lift a pad/trace. Get some solder wick or a solder sucker to get the old solder out. If you plan on doing a lot of repairs in the future (or have money to spend) get a hakko desoldering gun.

#9 5 years ago
Quoted from tp:

I have a board from a time machine I can practice on. I'm assuming I'd apply heat to backside and grasp transistor with needle nose and pull out? Correct way > assume

It's going to be tough to heat all three legs at once. If you don't have a desoldering tool, the easiest option is to try to clip the transistor off the board with wire cutters so that you leave as much of the leg as possible sticking out. Then you can apply heat to each leg one at a time and pull them out with pliers. But I'd recommend at a minimum to pick up a spring loaded desoldering pump like the one that pinball life sells. They're under $10 and make this a lot easier.

You can also test transistors with any dmm on the diode setting, even while they're in the board. Just compare readings between the transistors for the left and right flippers if they don't match, ones bad.

#10 5 years ago

I cut the legs and remove each one, one at a time.

#11 5 years ago

Thanks guys keep the info flowing. I plan on ordering the stuff I need tonight hopefully. Someone mentioned elsewhere I may wanna replace the associated resistors also?

#12 5 years ago
Quoted from zacaj:

It's going to be tough to heat all three legs at once. If you don't have a desoldering tool, the easiest option is to try to clip the transistor off the board with wire cutters so that you leave as much of the leg as possible sticking out. Then you can apply heat to each leg one at a time and pull them out with pliers. But I'd recommend at a minimum to pick up a spring loaded desoldering pump like the one that pinball life sells. They're under $10 and make this a lot easier.
You can also test transistors with any dmm on the diode setting, even while they're in the board. Just compare readings between the transistors for the left and right flippers if they don't match, ones bad.

This is the correct method but with one modification. Use the existing solder to protect the board.

Clip off the component leaving as much leg as possible.

Use pliers or a hemostat to grab the leg.

Heat the component until the solder melts and pull it out. Make sure they didn't bend the leg on the bottom. If so push it through.

Now that the leg is gone use a solder sucker, desoldering gun, or wick to clean the hole. You may need to add solder if using a sucker.

I used to be very concerned about reusing the old component but this places the value of the component over the value of the board. Best to be safe and protect those traces.

#13 5 years ago
Quoted from tp:

Never tested the transistor as I dont have the tool shown above but can order it.
Pretty sure it's the transistor as when i discussed flasher stuck on with chaz(stern)he seemed to think that was the issue. As for flipper all signs point to bad transistor but again haven't tested.
I dont have a solder sucker guess I need to get one. I haven't removed any transistor as of this postung.

Solderwick usually works fine for smaller stuff.

A word about solder...don't use acid based solder. I would get some '60/40 rosin' (tin/lead) solder, great for a person trying to learn the skill. Lead free solder has a higher melting point than lead based, and while it flows OK, just not the greatest when compared to 60/40. Switch over to lead free later if you feel like it.

As vid mentioned, find some junk stuff to solder on (even if it's simply a wire) and have at it. Practice makes perfect!

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edit: The solderwick shown is 0.025" (fine). They make wider stuff which is what I normally use.

#14 5 years ago
Quoted from tp:

So my Metallica pro has been down for a while. With the new code and all it's time to get it back up and running. I got a new soldering iron that was recommended here for Christmas so no more excuses.
I'm looking for good advice so please feel free to give it. I'm at the stage where I'm gonna order the parts.
Heres what's wrong.
Left flipper stuck up when game powered on til it blows fuse or powered off.
Left back panel flashers stuck on.
I've concluded that transistor 15 and 21 control these and need to be replaced. Should I replace anything else while making this repair?
Please feel free to point out any tips and useful information as this will be my first attempt at this.
Thanks tp[quoted image]

Since you are local-ish, if you are willing to make the drive I will teach you how to solder and desolder. If not here are my tips. I use wire cutters (hakko wire cutters - image below) to cut the part out. Example: if its a 16 pin dip I cut every lead at the package body. Removing the plastic chip and leaving only the legs soldered to the board. Next I take my desoldering gun (but you can use a soldering iron too) on the back of the PCB board. When the solder melts I remove the metal leg from the via (hole) and next suck the solder out. Using an iron wait for the solder to melt and remove the leg, then come back with a mechanical sucker or wick (I would suggest wick for a beginner) and remove the remaining solder.

Tips: (1) it may be helpful to ad fresh solder before you start. If seems to help the older solder melt faster. The less time the solder iron is in contact with the PCB the better. (2) when using wick, apply solder to the wick first on the bench. Then use the wick on the PCB via or pad. It helps the wick work faster and again less heat on the PCB. (3) when cutting out the component be careful not to scratch or damage the PCB. (4) if thru hole legs are bent over on the bottom/back of the PCB use the cutters to flush cut with the PCB. this will make it easier to remove when desoldering.

Finally, it might help if you post and picture of the transistor you want to replace. And did you test the transistor with a DMM?

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Edit grammer mistakes.

#15 5 years ago

duplicate post.

#16 5 years ago
Quoted from zacaj:

...If you can get the part out you've already done the hard bits. Might as well put a new part in at that point.

Good point. I usually do that too unless I don't happen to have the part handy...but I still test to see if that was the culprit.

Quoted from Turtle:

Since you are local-ish, if you are willing to make the drive I will teach you how to solder and desolder...
Edit grammer mistakes.

Kudo's turtle

#17 5 years ago
Quoted from Turtle:

Since you are local-ish, if you are willing to make the drive I will teach you how to solder and desolder.
[quoted image]
Edit grammer mistakes.

I'd make the drive down with the board and parts if you have the time to stand over my shoulder and walk me through the process that'd be super cool.
I've soldered plenty of things under the playfield before just not anywhere as delicate as the pcb board. I'm a fast learner when hands on, not so much from the manual.

#18 5 years ago
Quoted from tp:

I'd make the drive down with the board and parts if you have the time to stand over my shoulder and walk me through the process that'd be super cool.

I sent a PM.

#19 5 years ago

Thanks ..gonna read it now. Below is pic of board I just took out. Any obvious signs on q15 q21? Bottom of 1st pic.

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#20 5 years ago
Quoted from tp:

Thanks ..gonna read it now. Below is pic of board I just took out. Any obvious signs on q15 q21? Bottom of 1st pic.[quoted image][quoted image]

No obvious signs. But should be very easy to test with DMM (it's either a NPN or PNP transistor) and very easy to replace. Do you know the part number of them? Or do you have replacements? I should have replacements but I need to know the part number.

#21 5 years ago

Stern pretty much uses STP22NE10L or IRL540N or 20N10L device which is a N-channel MOSFET of 100V and 20 to 22 amps.

If you work on DE, Sega, Stern or some Gottlieb games, you should have a few dozen or more on hand.

#22 5 years ago

Q15: STP22NE10L / IRL530N / IRL540N
Q21: TIP122

#23 5 years ago
Quoted from schudel5:

Stern pretty much uses STP22NE10L or IRL540N or 20N10L device which is a N-channel MOSFET of 100V and 20 to 22 amps.
If you work on DE, Sega, Stern or some Gottlieb games, you should have a few dozen or more on hand.

Quoted from jfesler:

Q15: STP22NE10L / IRL530N / IRL540N
Q21: TIP122

Thanks for the info. Unfortunately I do not have these. However, they will be included in my next order.

#24 5 years ago

Backside of q15(bottom) in contrast one above looks good?

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#25 5 years ago

Looks like it got hot. Also appears to have a crack around the bottom lead

#26 5 years ago

This is after replacing the transistor?

The continuity checker on your multimeter can verify. I usually compare a leg of the component against a related trace. You can see the traces easily on these boards.

#27 5 years ago

Backside of q21 looks good?

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#28 5 years ago
Quoted from jfesler:

This is after replacing the transistor?
The continuity checker on your multimeter can verify. I usually compare a leg of the component against a related trace. You can see the traces easily on these boards.

No I just took board out. Examining transistors that i think are bad because....
Q15 is the drive transistor for left flipper.
When I turn on game left flipper locks on until it blows fuse next to flipper coil or I turn game off.
Q21 drives left back panel flashers. Flasher rattled loose fell off backpanel touching wires and shorted q21? Put new flashers in they lock on til they over heat and fail. This is my reasoning for thinking transistor q15 q21 are bad.

Searched all over for my multimeter but it eludes me. May be easier to go pick a good idiot proof one tomorrow. Any good ones to be had at lowes as its local.

#29 5 years ago
Quoted from mbwalker:

I just got this gizmo based on some other postings on Pinside. Seriously impressed. Checks transistors and FET's (and a lot of other stuff too). Checked about 3 transistors in less time than it took to type this. Don't even have to worry about connecting wire to the correct pin. Just hook it up, press test...and it figures it all out.
As Schud eluded, take the part out to test.
[quoted image]

Thank you for that. Ordered!

#30 5 years ago

Unless the package is obviously blown (in which case, you'll *know*).. a simple visual inspection isn't gonna cut it. Gotta test it with a meter, ideally one that can do a diode check. Barring that, swap the suspects with known good replacements. But, I tend to avoid risking removing a solder pad until I know I have no other choice; boards aren't cheap to replace.

#31 5 years ago
Quoted from tp:

Backside of q21 looks good?
[quoted image]

It looks like solder was flowed well. Nice and smooth fillets and I don't see any angular ring around the lead (I zoomed in in the pic). Compared to other factory solder joints I see in the picture...solder looks fine. Unless the leads had a containment on them. Ohm it out if you want to be certain.

#32 5 years ago

You could maybe clean this up just a tad if you want...but I think it's OK.

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#33 5 years ago
Quoted from NPO:

Thank you for that. Ordered!

np. It gives you the B-E voltage drop and and beta (current gain, which is important). Cheap Chinese stuff...but darn it, it works great.

#34 5 years ago
Quoted from jfesler:

Unless the package is obviously blown (in which case, you'll *know*).. a simple visual inspection isn't gonna cut it. Gotta test it with a meter, ideally one that can do a diode check. Barring that, swap the suspects with known good replacements. But, I tend to avoid risking removing a solder pad until I know I have no other choice; boards aren't cheap to replace.

Can I pick up a meter locally that will perform these tests you speak of? Lowes home depot harbor freight? Lmk thanks.

#35 5 years ago

Thanks to the generous offer of @ turtle to walk me through the process of fixing this board. Before I head off to his place I need to gather the parts.so my priorities right now are to....
Find a meter locally that will test q15 and q21
Gather all parts I could or may possible need before heading to turtles place. Suggestions on meter and parts I should have?
Thanks to everyone trying to help its appreciated.

#36 5 years ago
Quoted from tp:

Can I pick up a meter locally that will perform these tests you speak of? Lowes home depot harbor freight? Lmk thanks.

Yes. Go to the electronic aisle at Home Depot. They have lots of DMMs. Any of them will do the tests you need to do. I bought their Klein Tools one and it’s awesome.

#37 5 years ago

Hey bud

I just replaced a few transistors for
My jp. It was simple.

I watched a video online. I use a simple iron and a 5 dollar meter from harbor freight. You’ll also need a soldier sucker.

But it’s simple.

#38 5 years ago
Quoted from tp:

Can I pick up a meter locally that will perform these tests you speak of? Lowes home depot harbor freight? Lmk thanks.

You actually can pick up a DMM that will test transistor current gain at HF. $20. Item: 61593 One thing I just thought of...I need to go back and check the part numbers of your parts in question. Not sure if they are FET's or bipolar. I bet the meter just checks bipolar (ordinary transistor).

I didn't see you mention you owned DMM, so that model would come in handy regardless.

Edit: TP122 is bipolar, so the HF meter might be able to test that directly. It is darlington tho which might give the HF some trouble. The IRL540 is a MOSFET. I doubt the HF meter will test it directly, but you can at least do basic D-S and G-S testing.

#39 5 years ago

Terry B offers tons of great information to help you get started on this check out his website

https://pinballrehab.com/

#40 5 years ago

You fix this thing yet TP or you blow your nuts off?

#41 5 years ago
Quoted from Blackbeard:

You fix this thing yet TP or you blow your nuts off?

Work in progress, life keeps getting in the way.

I'll definitely update.

#42 5 years ago
Quoted from tp:

Work in progress, ...

What...blowing your nuts off or fixing? Curious minds want to know...er, maybe not.

#43 5 years ago
Quoted from mbwalker:

What...blowing your nuts off or fixing? Curious minds want to know...er, maybe not.

Parts ordered....nuts still attached for now.

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