The Aussie Pinball Arcade
Aussie Pinball Forums => Technical Matters => Pinball Repairs / Problems & Assistance => Topic started by: Dimsims on March 15, 2015, 01:16:51 PM
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Hi all,
I have a Data East power supply (520-5047-00) thats playing up ^&^
The R15 resistor is as hot as hell (finger sizzling lol) & the dmd screen isn't working as a result of the power supply.
I tried the dmd in another machine and it works.
I've replaced allot of parts in the HV section but still no good.
Any ideas ?
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Ideas? Yes.....get a multimeter and start measuring voltages. You cannot "guess" a problem like this and simply shotgunning parts is not a fast, easy or sensible way to find the fault.
These are very simple, regulated supplies so a measurement of all the voltages should reveal exactly what area your fault is in which will narrow it down to a few components.
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Ideas? Yes.....get a multimeter and start measuring voltages. You cannot "guess" a problem like this and simply shotgunning parts is not a fast, easy or sensible way to find the fault.
These are very simple, regulated supplies so a measurement of all the voltages should reveal exactly what area your fault is in which will narrow it down to a few components.
OH yes I forgot to say I tested the voltages @.@
All is good bar the 68v, is only reading 22v.
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Did you already replace D9, 68 volt zener?
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Check connector CN1 on power supply. Make sure no burnt pins or cold joints.
Test for 68 volts DC at Diode D5, banded side positive, negative to ground.
If no/low volts, test/replace the following components in order.
Resistors
R8 - 47K, R11 - 330K, R12 - 1.5K and R15 -500R.
Diodes
D5 - IN4004, D6 - IN5228(3.9v zener) and D9 - IN4760(68v zener)
Transistors
TR1 - MPSA92 and TR3 - MJE340
Also capacitor C10 is important for 68 volts.
The above components comprise the entire 68 volt section of the power supply board.
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Thanks heaps for the info Steevsee ^^^
Ok, so I've tested the D5 diode, it was working but I replaced it anyway and tested for 68 volts and got 140 volts *!@
At the CN5 68 volt pin, its reading 25 volts
R11 - 330k tested to 356k, so that was replaced.
Also R8 & R12 tested ok.
I've replaced: D6 - 1n5228, D9 - 1n4760, TR1 - MPSA92 and TR3 - MJE340
Im waited for caps to arrive for C10 & C11
68 volt test was done after parts were replaced.
Could it be the C10 cap ?
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Desoldered the C10 & C10 caps, tested them and both caps test "OL" (over limit)
Not sure if my multimeter is playing funny buggers ?
Hopefully I get the new ones tomorrow #@#
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My bad on the diode voltage reading.
The input volts is 100vdc at the diode and without a load, your reading is probably OK.
Hopefully C10 will improve your output volts.
C11 is part of the negative volts DC circuit, but won't hurt to replace it as well.
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The caps for C10 & C11 showed up today, I soldered them in but still no go *!@
Not sure where to look now ?
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So you're still only measuring around 20 volts output?
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Yup, 23v
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Just checked circuit again.
Looks like C13 filters the final stage voltage in this circuit.
Seems to be the only other possible candidate. !@#
Edit.
Just realized my JP has the same 68 volt circuit as your board.
Tomorrow I will measure my voltages at various points along the circuit.
This may hopefully help narrow down the problem.
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Just checked circuit again.
Looks like C13 filters the final stage voltage in this circuit.
Seems to be the only other possible candidate. !@#
Edit.
Just realized my JP has the same 68 volt circuit as your board.
Tomorrow I will measure my voltages at various points along the circuit.
This may hopefully help narrow down the problem.
Thank would be great ^^^
I did replace C12 & C13 already, so yeah I'm not sure.
As I said in my first post, the R15 resistor is getting super hot, enough to melt the solder.
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Ill check my R15 Tomorrow as well. ^^^
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Here is a picture of it before I started replacing parts:
(http://ttrracing.com/admin/Pictures/DESW/Bat/1.jpg)
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Is that thick trace going under R14/R15 burnt? Looks burnt.
Also wonder why the extra cap on R14? !@#
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Yep that trace is burnt to high heaven %.%
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R15 certainly has been getting hot!
How's the continuity between lh side of R15 (bottom in your pic), and banded end of D6?
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I found this searching the net:
http://translate.google.com.au/translate?hl=en&sl=fr&u=http://www.flipjuke.fr/alim-data-east-perte-68v-apres-t92534-20.html&prev=search
Same symptoms as mine, but never found a solution &^&
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Was having a look on the net re this problem and found the following link:
http://www.willcoxonline.com/pinball/
Scroll down to the heading: Dot Matrix Display stopped working.
Hope this helps.
Cheers,
Andy
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R15 certainly has been getting hot!
How's the continuity between lh side of R15 (bottom in your pic), and banded end of D6?
If that is open circuit, then I would expect to see nothing at D6. Seems there might be some jumpering under the board that is incorrect.
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Yes bottom side of board pic would be good. !@#
The article linked by Andy (andtan) is also worth looking into, especially if any charring around TR3 C/E.
Dimsims
Sorry I didn't get those measurements today.
On days(Nights) off after tonight so will definitely get them done tomorrow.
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Thanks Guys ^^^
OH its charred alright !*!
(http://ttrracing.com/admin/Pictures/DESW/Bat/2.jpg)
I did some scraping off the black charred stuff and there ended up being a fairly big hole where TR3 goes.
(http://ttrracing.com/admin/Pictures/DESW/Bat/3.jpg)
TR4 not much better.
Now I have to think of a way to fix it lol.
So should I scrape as much of the charred stuff off the board ?
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I wouldn't go too crazy scraping yet.
Basically bad charring produces carbon which can conduct between pads but most areas should be fine.
As far as the transistor goes you might get lucky as it's mostly supported by the heatsink.
You'll just need to jumper the legs to the relevant traces.
And leave TR4 alone.
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If the heat sink doesn't do a good enough job of holding the transistor in place, you could look at using an epoxy such as JB Weld:
http://www.jaycar.com.au/Service-Aids/Chemical-Aids/Adhesives/J-B-Weld-Epoxy/p/NA1518
to fill in the burnt out area. You'd need to put something underneath the board to hold the epoxy in place as it sets - I've found that most clear plastics from product packaging works well for this - just tape it in place.
Then drill some new holes for the transistor and jumper the legs to the relevant tracks as suggested by Steevsee.
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I've managed to get the Transistor to sit there with the support of the heat sink.
Plugged it back it the machine to test, now the R15 has stopped heating up, but only getting 5.8 volts on the 68 volt line &^&
I can feel a new board in the works lol
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That seems like some good progress if that resistor is no longer overheating. ^^^
In the article, the guy's 68 volt zener got fried before he fixed the overheating issue.
Dare say the same thing has happened here.
Also the board looks OK overall, but probably worth dealing with that hole once it's all working.
http://aussiepinball.com/index.php?topic=7422.0 (http://aussiepinball.com/index.php?topic=7422.0)
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In the article, the guy's 68 volt zener got fried before he fixed the overheating issue.
Dare say the same thing has happened here.
Will give that a go, I just found my spare 68v zener that I had :D
Also I now need a 1N5379 110v zener as I blew it last night lol
I was testing something near it slipped out it and shorted & killed the D10 110v zener @.@
Trouble is where do I find one ? Jaycar & RS Components don't have them ?
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I replaced the 68 volt zener, did another test & got 66.8volts $#$
Now just need to find a 110volt zener for D10 !@)
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@@* I've been keeping up with this thread with interest. It wasn't looking like a good result there for a while. Will you look into fixing that hole now or let it be?
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I replaced the 68 volt zener, did another test & got 66.8volts $#$
Now just need to find a 110volt zener for D10 !@)
Nice work. Definitely worthy of happy dance.
Thanks to Andtan for the vital clue. ^^^
I'll check to see if I have that 110 zener.
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+1 Nice work.
Looks like you almost there! And to think you had almost given up.
If Steevsee doesn't have the Zener, there are some at:
Element 14:
http://au.element14.com/nte-electronics/1n5379b/diode-zener-5w-110v/dp/2143709 - Only 74 cents each, but postage will be about $13 !*!, or
From ebay where you can get 20 for $14 with free postage from China, in about 2 weeks *!@
http://www.ebay.com.au/itm/190918809986
They are listed as 1N5379B, but that seems to be the correct one.
I've had a look, but unfortunately I don't have any. If you were to grab the 20 from China I'd be happy to grab some from you and split the costs to make it more worthwhile.
Cheers,
Andy
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Yeah thanks heaps andtan for the link to the checkpoint page ^^^ that page was the key *%*
I threw in a 1N4764 zener (100v) just so I could test the DMD and POW!! SHES WORKING !! #@#
Thanks heaps guys !! Couldn't have fixed it without you guys @@*
If you have one Steevsee, let me know how much and ill send you some $$
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Great result!
I don't have that zener either unfortunately.
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May have to go the ones from china !@#
At least ill have spares.
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Any combination of Zeners in series will do the trick just as well.
IE: 2 x 55V in series equals 110V