Can I post videos? I have a Hot Tip doing strange things when powered on and rather than trying to describe it, I thought I could post a 30 second video

Greetings gents!! Question, I have a Firepower and I would like all of the boards looked over, tested, and repaired. Could anyone here recommend members that are reputable repair sources for system 6?? Thank you!!

sohchx, I can repair and test them. Wait is very short right now, I'll pm you.

video didn't really have much to show so here is the description!

I have a "Hot Tip" (electronic) that is doing unpredictable things. The cpu and solenoid boards look like they have been replaced/repaired in the past (the battery has a new socket and a couple of the transistors appear to be new)

When I first got it, left kicker coil was on solid and its probably toast. I unsoldered it and left it for now.

When powered on, usually it comes up with the game over sound but even though I have set the switch's to have 10 games, I get zero and am unable to play. It will let me go into diagnostics via the cpu-board pushbutton though. But sometimes it comes up with no sound and all zeros on the display. Nothing works.

It occasionally does strange things by itself if left to sit. Every 30 seconds or so it will make some sounds and usually the display will change the number of credits left or the score of player 1 will count up by itself.

I ran through diagnostic mode, The cpu diags always pass (2 flashes,) after that test 1 (lamp) is good, test 2 (solenoid) works for most of them (a couple will not fire) but test 3 (switch) displays a lot of numbers (sometimes 5-8 numbers) - some of which I have visually checked to make sure they are not closed.

In some of the threads there is mention of capacitors going bad and causing strange behavior, does this sound like it? I am reluctant to start unsoldering caps at random just to check them but i will if I have to.

A lot of your issues sound like they would be resolved if your boards where bulletproofed per vid's guides. =D

Before messing with replacing IC sockets or components, start with this. Reflow the solder on the male connector pins on the two top right corner of the driver board (switches). The 40 pin interconnect is always suspect too. Relfow as needed.

For the displays, resolder the male MPU 9 pin connectors across the top side of the MPU.

Been working on getting all of my system 7 and 11's up to snuff on the power boards, replacing the caps and the high voltage sections, I'm running into a problem finding an economic solution to replace the 18000mfd 16v axial capacitor...

Vid, or anyone know of a non-expensive solution to replacing this cap?

some have suggested 15000mfd, but I don't know if thats safe

12000uF to 18000uF radial or axial cap will work in that power supply. If you use radial, zip tie the cap in place and run a short length of insulated wire.

Thanks guys!!!

adding a comment so I can find this and ask questions. Starting on a buddy's Joust soon

Thanks Vid1900 for this blog. It helped with troubleshooting my Time Warp.

So, I have a real head scratcher of a driver board on the bench today!

It's from a black knight. Lots of socketed ICs, including all 3 pias

I bead blasted it to clean up some alkaline corrosion around the relay area, front and back.

New interconnect, headers, lamp resistors and sockets. Socketed ICs tested in another driver board, they are OK.

There's a short on the 5v rail somewhere that I can't find.

I pulled the first 10 pin interconnect header back out to make sure it isn't there

I pulled the 9 pin .156 header in the lower left corner of the board under there.

Attach it to a CPU, and it fails to boot. Not even a flicker, just locks up.

I hooked a 5v battery up to it, all 5v pins on the left side of the board measure 0, and the battery gets really hot.

Any ideas for pinpointing the source?

John,

One method that I have used in the past to find shorts is to connect a variable lab supply with variable current limiting. If it is a 5V line, then set the voltage down to one volt no load. Set current limiting down to zero, then connect. Then turn up the current limit and watch the meter... keep the current below what the smallest trace will take for the boards you are testing...

I have actually "blown open" shorts that are hairline shorts using this method. If you turn up the current to the max that the traces can take, then you can use a thermal tracer to follow the temp of the traces... the fault path will be hotter than anything else. If your lucky, the short won't be under a component... but we are never lucky are we?

Chances are it is a stray solder ball or wire fray fragment lodged under a chip.

Good luck!

Mac

Back in the module repair depot we used to have these board sized temp sensitive plastic sheets (kind of like a mood ring) that we would lay over the board and connect a power source and it would light up as the area got warm. Maybe something like that? Or a thermal camera?

Barring that, you are going to be cutting traces me thinks.

Vid, it came in dead. My typical mode of operations is to replace header pins and sockets on these boards, along with the interconnect, so I did that, and it's still dead. I took it a step further and pulled all the sockets and new header pins and the 3 ICs that weren't already socketed. So, I have a bare board on the bench with a short that I can't find!

I even clipped all the little caps on each ic, thinking one could be shorted.

I spent all day smoking a pork shoulder and my eyes were starting to get real tired and dry, so I packed it in for the night.

I'll get back to it with fresh eyes tomorrow.

Got a stronger supply?

Crank up the amps and see what glows.

never mind the board, lets get back to the great sounding smoke pork shoulder?

There is a 100uF 5v filter, check that sucker out. Caps generally fail open, but maybe it is shorted. RUn a screwdriver along the entire 5v rail looking for a solder bridge. Wire brush the entire board and hope you knock a short off.

Are the PIAs hard soldered? Pull the ground pin out on each one and any chips still on the board. The switch matrix chips are not well protected from incoming shorts. Solenoid voltage could zap one out into a short circuit failure mode, i have seen them exploded out before.

I found it after I set it aside for awhile.

Alkaline damaged boards always seem to be extra challenging. What looks like an easy clean up turns into a nightmare!

I bead blasted the corroded sections of this driver and rebuilt it, but unfortunately, the bead blaster removed the solder mask on some traces and that allowed an adjacent solder pad to short out to a trace - and look like it belonged that way!

image.jpg

A little braid, and we are back in business!

Vid, can you list out what components are required to replace 3J1 and 3J2 for both the power supply board and the connectors?

I found this for 3J2, but I'm not familiar with that type of pin.

https://www.greatplainselectronics.com/search.asp

thanks,
-mof

OK, so the male and female pins for the female connector are standard. But for the piece you mount on the board it has its own special pins that are built in. Then the female connector is special due to the shape.

So for a guy who already has a full collection of 0.93 parts -- I just need the new piece connected to the board and the new 6-pin female connector due to the shape. I already have the pins that will go inside the female connector.

Am I interpreting all this correctly?
Mof

Can you recommend a resource which describes what voltages to expect and how/where to measure them on the power supply board?
thanks,
mof

Looking at a 2008 Clay guide online, I see what voltages to expect, but not where/how to measure them:

The "power supply" (that is, the transformer, the power supply board, and the backbox attached bridge rectifiers/filter capacitor) outputs the following 7 voltages:

+5vdc regulated logic power.
+12vdc unregulated, often called "unregulated 5 volts" by Williams, because on the CPU board the unregulated 12 volts gets knocked down to about 5 volts.
+18vdc lamp matrix power (for game controlled lamps).
+28vdc solenoid/flipper power.
+/- 100vdc score display power.
6.3vac General Illumination lamp power.
+50 volts DC (for flippers), Firepower2 and later, via an additional flipper power supply board.

Ok, I did a check on my Gorgar System 6, and got the following values:

TP results on the power supply board:

3J3, solenoids, 40 VDC
3J4, lamps, 22 VDC
3J5, logic, 5 VDC
3J5, display, 90 VDC (used the updated parts to drop this voltage -- expected)
3J6, logic, 5 VDC

So, most important, logic and displays are great.

I'm wondering about lamps and solenoids -- are 22 and 40 VDC ok?

(As for the brightness and power of the solenoids they all seem perfect when playing.)

thanks for your input...
-mof

Coils and controlled lamps voltage has zero load.
So the voltage is a bit on the high side, as expected....

Thank you -- can someone elaborate a bit more about this response? (with respect to "having load" and which voltages should sometimes be a bit higher than normal?)
-mof

When a coil activates it draws current.
Because of the current draw and resistance the voltage will drop a little.
But a coil isn't constantly activated....
That is why is zero load the voltage is a bit higher than normal.

The same goes for the 18/22 volts for the lamps too.
Try a measurement while the game is in attrack mode (with controlled lamps on).
Compare this measurement with the game in test mode (controlled lamps should all be off).
You will see the voltage fluctuating while the game is in attrack mode and steady in test mode.

Vid is correct.
Which is why it is called an "unregulated" power supply.

A regulated supply would have a ummmmm regulator in the circuit that would be watching the output and compensating for the load change and resultant drop.

The 12v supply in B/W games is a good example of an unregulated supply. When you add mods you need to watch the voltage so that you do not pull it down too far and cause weirdness.

Hey Vid, I have this board in my gorgar, which I am repairing, Is it the correct board for this game? The driver board was cooked from a miss matched wire connection (I already asked you about the results of this) This could be hacked together project machine so it would not surprise me if this was the wrong board.

I bought the WAN-HVP-KIT from great plains and replaced all parts but the transistors ( that replace the obsolete SDS-201 and SDS-202 transistors) and I am now I am getting no display and my F1 1/4 fuse is blowing. I also change out the yellow caps and replaced them with 450v 22uf caps. I did not have the recommended I did not have your recommended 15000f 35v, so I did 3 4700f 25v in parallel.

my kit came with 6 diodes 4 of which matched with ones the board, but the final 2 had different numbers than the ones near my one yellow cap ... I assumed great plains just put a compatible part in there and I installed them.

What have I done wrong? Are my 450v 22uf cap wrong for the yellow ones?

Okay, I think I see what i did. the WAN-HVP-KIT had an extra set of diodes a pair of 1N4764 (100v) I mistakenly replace the 1N4001 diodes that were on this my old board which are 1A 50V. Now I need to try to find one of those on some old scrap boards.

I just successfully completed this mod on my Firepower. Thanks so much for the info. Is there any mod to reduce temps from the lamp row drive resistors (R95, 100 etc.) that are also screeching hot?

The MOSFET mod is a nice idea. But in this configuration the FET's are driven by a -18 Volts Vgs which is dangerously close to the absolute maximum rating of -20 Volts. I wouldn't do it this way. A 50/50 resistor divider would be very nice but is a bit impractical....

So what do you think would be the worst-case scenario with this mod in place?

I had the unit powered up while replacing a light on my SS Hot Tip table, I dropped the table and the right flipper solenoid struck the metal bar on the cabinet and shorted - smoke and everything.
i checked the fuses, only the 7.5amp main fuse needed replacement. I've replaced the melted solenoid but there is no power to the flipper, the left one works ok however.

I don't see anything obviously burned, cracked or broken on the solenoid board around 2J12. Checking the schematics, it looks like the flipper path is pretty basic compared to the rest, could the flipper relay be partially dead and allow only one to work or is it more likely something else?

sadly yes. left side I have power, right side I don't. I thought since I blew the main fuse to the cabinet I might have burned a trace on the solenoid board but I don't see anything obvious. I am guessing I fried a component somewhere, just trying to trace backwards and find the culprit.

update...checking the schematic, there is a blue wire directly from the pf fuse to each flipper solenoid, so I checked voltage at each point and found I had a bad solder connection on the replaced solenoid (power when checked wire, no power when checked solenoid.) Reflow and all is ok now...whew!

Got a nice souvenir out of it:

blogger-image-534105234.jpg

Another marvellous super detailed guide. It's interesting, I learned such lot of things from your tutorial. Great work.

I have a World Cup with the yellow caps and diodes. Since this game doesn't require them, I'm going to take them off rather than replace/leave them in.

In reference to VID fusing the brideges I use these neat little gadgets.

http://pinballreplacementparts.com/products/product-0003

rectfuse.jpg

Awesome thread.. Thanks to all who contributed ideas and tech info.. I had no idea there were so many fundamental flaws in my Black Knight.. As someone who had a house fire because of an electrical problem about 18 months ago, I know now I'm not going to leave the room with my BK plugged in at least until I get my fuse kit I just ordered! (No, the fire wasn't pinball related!)

-Steve

I've made the Bridge Board for this kind of problem.
It does away with both bridges and the large capacitor and adds fuses and control leds for both voltages.
Available in the US via Big Daddy Enterprises and in Europe directly with me.
http://bigdaddy-enterprises.com/boards/boards-index.htm#newboards

Brug Bord 01 klein.jpg
http://home.kpn.nl/p.koch3/bridge_board.htm

Peter
www.inkochnito.nl