View Full Version : DSR6000 Power Supply Question

01-19-2004, 10:47 PM
Just bought a broken dsr6000 from ebay. It looks like it had a lighting hit and one of the lnbp chips is damaged. Looked over the rest of the board and everything else looks normal. I tried to plug it in and the HD would not spin (heard clicking and fan would spin) smelled something burning. Not Good. I have a spare powersupply that is good so I switched the power supply and still nothing. Here's the question: If a lnbp chip is blown will it keep the hd from spinning up? What else should I look for on the MB that would keep the hd from spinning?

01-20-2004, 09:20 PM
You have much more than a lnbp chip gone bad. The reason the supply is clicking is the load is too great because its shorting to ground and the supply is shutting down. You'll fry the supply if you keep doing it. You have at least a bad tuner and lnbp chip, probably a bad main chip as well. You gotta figure out whats holding down what line and free it so the supply will free up and power normally. These are VERY hard fixes, especially if you dont have the right tools and experience........

01-21-2004, 11:51 AM
Greeks absolutely right. More than likely the tuner associated with the blown LNBP chip probably has it's 3v line shorted. Depending on the extent of the damage it is possible that a new tuner and a new LNBP chip might very well fix the beast. Best thing to do (providing you have the correct tools) is to remove both the damaged LNBP chip and its corresponding tuner. Then check for shorts on the power supply busses. If all is well you can try and fire it up.

01-22-2004, 11:03 AM
I think Im up for the challenge. I will look at it as a learning experience. I have already fixed a couple of tivos with your help (tuner and lnbp replacements) so I have some experience. I have removed the bad lnbp chip and like you said it didnt help. I will remove the tuner tonight and see what happens. After I remove the tuner how/where do I check for a short without connecting the power supply (I have already downloaded the t60 schematics). Do you know where I can get a tuner and how much it would cost (I know their hard to come by)? Have you ever repaired a tuner? I have a couple of bad ones and I was thinking I might be able to make 1 good one. If you have the time I would appreciate any help on this project.

01-22-2004, 11:30 AM
Loopie This is the way I would troubleshoot that board.

Disconnect the power supply and start checking the resistance between ground and 10 pin power connector.. The connector is numbered 1-10. Pins 1,4,7,10 should show a short. Everything else should not. Generally speaking a short on the 24 volt line (pin 9) indicates a shorted LNBP chip or a bad capacitor on that buss. The 30 volt line (pin 8) heads for both tuners, so a short here will definitely indicate a failed tuner or pair of them. Pin 6 is 5V and pin 5 is 12V. I have never seen a short on these busses, but I would guess the game is over if you see a short here. Pins 2 & 3 are the 3V supply to the tuners and most of the chips on the motherboard. A short here will more often than not indicate that he STV0299 chip on the tuner has failed, but could be anywhere on the board. Best thing to do here is remove a tuner at a time and see if the short goes away. I have been very successful with simply unsoldering pin 22 on the tuner and by moving it have been able to determine which tuner has shorted. i.e. I center it in the hole and essentially disconnect the 3v in to the tuner. If after removing both tuners you still have a short on the 3V line look at the modem. I would remove that chip as well. If after all of this you STILL have a short on 3v then it is probably one of the larger chips on the board. I would at this point junk the board as it is going to be more of a pain than it is worth.

I am working on repairing a couple of tuners that I think might just need the STV0299 chip replaced. I have a few of these on their way, and time will tell if I am successful. As for a source of tuners, that could be tough, but ask around on the board. There are some very good sources of parts out here.

01-22-2004, 12:50 PM
Thanks for the info I will check it out tonight.

01-22-2004, 11:22 PM
Thanks for the help guys, Everything went good (except I burnt myself with the soldering Iron again). I removed tuner 1 and that fixed my short problem. Got to updating database screen and would not go past that. I removed the modemtest file and it booted fine. I am working on fixing a tuner that I have so hopefully it goes well. Chazbell I will paypal you money tonight for 3 lnbp chips.