Arcade Collecting > Pinball
High Voltage not high enough
Neverending Project:
I am beginning to wonder if it might be the rectifier that has a problem. According to marvin3m, the rectifier should show 150V at its TP2 with connector J3 removed, and 230V with it attached. I am seeing 185V and 260V respectively. So I wonder if this extra 30V it causing the problem with the HV not being regulated correctly.
But I did completely rebuild the rectifier too. Hmm, I suppose there is the possibility that I could have botched something in my repair job... OK, maybe I will pull the rectifier again and take a closer look at all the components I replaced.
ChadTower:
Did you test the recitifier out of circuit? It's easy - it is four diodes.
Neverending Project:
To answer your question: no. But all three rectifiers on the power-supply board are brand new. And I used 200V 35A replacements, so they should be good-to-go.
But I was just reviewing the site where I bought the power-supply rebuilt kit (bigdaddy-enterprises.com), and saw that the kit included four 1N4004 diodes. According to Clay, these are used for the 170V for the score displays. He (Clay) says to replace the stock 1N4004 with 1N4007 or better. Do you think this might be the issue?
Oh, and of the other three bridge rectifiers I just found out they aren't for the HV circuit: BR1 is used to convert 7.8 VAC to 5.5 VDC, BR2 converts 12 VAC to 11-16 VDC, and BR3 converts 49 VAC to 43 VDC. So they shouldn't affect the HV at all. But now those 1N4004 look suspicious to me...
Update: Nah, from what I can tell, the only difference between the 4004 and 4007 is that the 4004 have a 400V peak reverse votlage, and the 4007 have a 1000V peak reverse voltage. Both should be good for this application.
ChadTower:
Yeah, Clay's guide frequently suggests upgrades on parts like that. So many people use it that I consider it vetted and trustworthy as far as replacement parts go.
Neverending Project:
OK, I am trying to narrow this down to where the problem might be. With only J2 connected (no backbox connections) the power supply board should show 150VDC at TP2 (according to Clay's info), and it is showing 190VDC. It seems like there is a problem with my power supply board, but if my voltage is too high, shouldn't the regulated voltage also be too high?
Also, according to the schematic the transformer should be sending 173VAC to the rectifier circuit:
But with no load I am seeing 190VAC on the transformer terminals. Should I suspect my transformer has a problem?
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