Pioneer Laseractive repair help

The problem is that the system partially loses power shortly after being turned on, it’ll last up to about 5min on a cold startup, but 1-2 seconds if it’s been running for a bit. When it does the it blinks on and off a few times before having the main light remain and reset light on but everything else off. I already recapped the power board due to obvious leakage of most of the filter caps. Unfortunately the owner used this unit for a fair bit of time in a malfunctioning state to play Sega Genesis games, those still work in the Sega PAC without issue, the nec pac loses power completely, not the unit in question but the problem here is almost exactly the same

 

You should be aware, I've got three of these systems, and only 1 good PSU board between them. I'm not surprised if you're having issues with it. Beyond that though, have you opened up the Sega PAC at all? These units have known issues with catastrophic leakage issues from the SMD caps. This was also the case with a factory-sealed PAC module I got. The caps were dodgy at the time of manufacture. I've recapped several of them, but it's a long process as there are many of them, and there's often significant damage to the traces on the PCB too. It's fixable if you know what you're doing, but very time consuming, and decent replacement caps will cost a bit too. If you've never opened up the PAC module itself, I'd recommend you don't put power through it again at all until you crack the case and inspect its condition.

 

I’m well aware of the issues with the Sega pac, hence why I’ve been doing most of my testing with my nec pac rather than the owners Sega pac, I will probably be recapping the Sega pac at a later time. I already recapped the nec pac and I know it works. I also did the power board in the laseractive itself. The problem however happens even when no pac is installed. I should be able to use a voltmeter to check things out this weekend but I feel like I’m flying blind.

 

I don't think I can offer much more help. I haven't attempted to repair the known faulty PSU boards I have. I'm perfectly comfortable poking and prodding boards with nice "safe" 5v logic flowing all over them, but as a rule I avoid sticking my fingers or probes anywhere near mains power. If you've got the knowledge to work on that kind of circuit safely however (I myself do not), you can find the schematics and circuit diagrams for the PSU board in the CLD-A100 service manual, which is available online. You're probably already aware of this though.

 

In your experience though have you moved your working one around to the other units and confirmed that the other components work?

 

Yep, swapping in my good PSU gets all the other ones up and running. This includes one I thought had a damaged spindle motor, as the disk didn't spin up half the time unless I gave it a push start. Of course, your unit could have different problems, but my money would be on the psu. It's a reasonably complex one, so quite a few potential points of failure. I suppose measuring the voltages and current draw for each rail under load would be a logical step if you wanted to try and figure out what's going wrong, but as I said I tend to stay far away from mains power, and have never tried to repair or trobleshoot a PSU.

 

That’s what I figured, it’s obvious that a voltage line is dropping, this behavior reminds me of an nes I fixed years ago that had a failure on one side of the bridge rectifier. As power supplies go it could be worse. Pioneer was good about labeling their stuff, biggest annoyance is the lack of separation between the primary, secondary and control circuitry. My bet is on one of the 14v rails. If I get it working maybe I can help you out with both of yours.

 

Could try upgrading the components on the PSU to handle higher current output. Or just swap them. These things can and do wear out. It reminds me of the Dreamcast when it warms up it can cause resets just like this continuing to cycle. In that case it's the metal pins that connect the mobo to the PSU moving just enough. I'm not aware of the PSU in the Laseractive having anything like this but it could be a harness moving for all I know. Maybe a solder joint is cracked and moving.

Recapping the entire thing is a PITA. I've got a Laseractive that doesn't output video anywhere near correctly when using MEGA-LD games (black and white, corrupt sprites, no video) but it works fine with Genesis games. Also no LD video. I don't think a recap will fix this (feels like a dead IC somewhere) but a recap will get me in a better state to figure things out.

 

I figured out the problem, the mode control ic was getting a bad clock reference due to a leaky cap on the INTF board, btw you might want to check the solder joints on the vertical board on the left side, that I found 3 cracked joints on that and one of them and I briefly had similar problems to your long dead unit. Those joints break easily if you remove the side board

 

Glad to see this repair has a happy ending. But wow, I was missing my laseractive I used to own until I read this thread. Thats x68k territory of nasty repair.