Re: Dell 2007fpb no power

Well I got my new rectifrier, soldered it in, reconnected all those tiny micro-Molex connectors, and plugged it in. And hey presto, it works! The little LED's on the bezel buttons came on, the backlight came on, and the bouncing "No signal" message appeared on the screen. Final tally: one shorted brdge rectifier, one blown-up electrolytic, one open fuse. Case closed. Thanks for the help.

Re: Dell 2007fpb no power

I pulled the bridge rectifier. The writing was on the back side. For future reference, it is a Vishay Seminconductors GSIB4A60, a 4 A 600 V rectifrier. This part is apparently obsolete and superceded by a GBU406. Widely available and cheap. I'm somewhat surprised they used such a high-rated part, and heat-sinked at that.

Re: Dell 2007fpb no power

Oh duh! No, you're not confused, I'm confused. I checked a square four-pin SMD called IC602 near the top of the board. I thought that was the bridge rectifier. Then I noticed BD601 but thought it only had three pins - it was hard to see the fourth pin hiding down the end of that thing. You are quite correct - BD601 is clearly the bridge rectifier and it's shorted out. Unfortunately, whatever markings it had were vaporized and it's just blank now. It's really hard doing all this without a schematic.

The hole at CN601 is where I pulled the blown...

Re: Dell 2007fpb no power

Well I kinda feel like I'm talking to myself here, but here goes anyway. I checked the bridge rectifier on the power supply board but didn't find any shorts there. However, I noticed a third heatsinked part, a three terminal jobber called BD601. The right hand terminal is connected directly to the burned capacitor. And it is a dead short from that terminal to the center terminal of BD601. That doesn't seem right. I'm going to take a wild guess that I need a new one. And of course, Mystery Part BD601 has no visible markings on it.

So can anyone...

Re: Dell 2007fpb no power



Yes, I did see that thread but it doesn't address the main power supply board. Anyway, while waiting for my new parts I checked both the chopper transistor and the big Schottky diode for shorts, but they seem OK at least by a quick resistance check.

I guess I'll just replace the fuse and the cap and then slowly run up the power supply on the variac while monitoring the current draw. If there's something seriously wrong early on the input side, it should manifest even if the board doesn't run.

While we're at...

Re: Dell 2007fpb no power

Hmm - my apologies for tacking onto this thread but I don't seem to be able to start a new one despite having registered and posted an introductory post already.

Anyway, I have a Dell 2007FPb with no power. Examination of the power board quickly showed that C605, the big 180 uF 450 V electrolytic is dead. The + lead was corroded clean through. Also, the main 4A fuse, F601 is open. Naturally I did not have either of these parts in stock. So while I'm waiting for them to arrive, any suggestions on what's possibly going on here? Is it likely that...

Re: New Members - please post your introductions here

Greetings all. Just discovered this forum and it looks great. I'm a retired programmer but electronics is my hobby. I'm a long-time poster over on the antique Radios Forum at antiqueradios.com.

Currently fixing a Dell 2007FPb monitor - may have some questions for you guys as I go along. Cheers!