Help with InFocus LP340 - Page 8

axlp · 1st March 2010, 10:16 AM

Hi.

I recently aquired a second hand Toshiba TDP-MT8 (Infocus SP7200 clone) which is totally dead. No fans, lights etc. Sounds like this is a common problem with the power supply. I have managed to source a schematic of the PSU. The schematic number 1615-06-00 seems to match a number on the board also looking parts/layout of the schematic they also seem to match. Any ideas if this is indeed correct?

Next step is to try and fix it. The problem I have is that the secondary side (18pin connector) voltages are all too low. e.g. 12v is 2.5v, 3.3v is 0.75v and -8.5 is -1.5. The power connector to the lamp is reading about 700v when the PSU is totally disconnected. Is this ok? Any suggestions for a fix? From reading this thread sounds like the Viper100a should be the first thing to check.

Thanks.

axlp · 2nd March 2010, 12:09 PM

Hi. I've just been testing the PSU. Looks like the schematic is good based on comparisons i've made so far. I can't see any fried components as others have and also can't see anything shorted on the primary side. Is it still worth replacing the Viper100a? Btw I think power to the ballast is ok as it reads about 380v DC which is what the schematic is saying. Thanks.

Gizmotech · 02:18 AM

99benns and axlp, give us a picture of the PSU (not the ballast).

axlp · 4th March 2010, 08:39 AM

Hi. Attached is a photo of the power board (not ballast) from TDP-MT8 (SP7200). There's a sticker on one of the large caps with details:

InFocus 510-1615-06 Rev 00
NMB 1F105J032PJW Rev 00

I've ordered some parts so will let you know how I get one.

Cheers.

axlp · 6th March 2010, 02:04 PM

Hi. Quick update. I've managed to get life back into the projector again. For how long who knows!

I ended up just changing these 2 components:

U2 - VIPer100a
C16 - 100uf 16v (swapped with 25v)

I think what happens is if the projector is left permanently plugged in the PSU bakes and kills the components. Really one of the fans should be permanently on providing it with air flow. After it shuts down (cools) I think i'll always unplug it. The lamp was only used for 362 hours according to the menu.

Hope this helps.

Gizmotech · 17th March 2010, 02:30 AM

Yep, C16 is the common culprit. Best thing to do is replace it with quality rubycon or panasonic caps then it should be ok for good.

axlp · 17th March 2010, 12:44 PM

Yes C16 was the only real problem component I found. I replaced the Viper100a due to the reported failures in other PSUs but the original tested ok.

The cap was reading about 75uf so a little on the low side. Also I replaced it with a 105 degrees rated one as the original is only 85 degrees. Given how hot these things can get in standby seems like it should be higher.

sujatapatil · 22nd April 2010, 02:26 PM

i have infocus LP350
i

marketta · 2nd January 2011, 12:30 AM

Quote:

Originally Posted by axlp

Hi.

I recently aquired a second hand Toshiba TDP-MT8 (Infocus SP7200 clone) which is totally dead. No fans, lights etc. Sounds like this is a common problem with the power supply. I have managed to source a schematic of the PSU. The schematic number 1615-06-00 seems to match a number on the board also looking parts/layout of the schematic they also seem to match. Any ideas if this is indeed correct?

Next step is to try and fix it. The problem I have is that the secondary side (18pin connector) voltages are all too low. e.g. 12v is 2.5v, 3.3v is 0.75v and -8.5 is -1.5. The power connector to the lamp is reading about 700v when the PSU is totally disconnected. Is this ok? Any suggestions for a fix? From reading this thread sounds like the Viper100a should be the first thing to check.

Thanks.

hi
you also have the electric scheme of the ballast
that is the power supply of the lamp?
thanks

marketta · 11th January 2011, 05:39 PM

Quote:

Originally Posted by axlp

Hi.

I recently aquired a second hand Toshiba TDP-MT8 (Infocus SP7200 clone) which is totally dead. No fans, lights etc. Sounds like this is a common problem with the power supply. I have managed to source a schematic of the PSU. The schematic number 1615-06-00 seems to match a number on the board also looking parts/layout of the schematic they also seem to match. Any ideas if this is indeed correct?

Next step is to try and fix it. The problem I have is that the secondary side (18pin connector) voltages are all too low. e.g. 12v is 2.5v, 3.3v is 0.75v and -8.5 is -1.5. The power connector to the lamp is reading about 700v when the PSU is totally disconnected. Is this ok? Any suggestions for a fix? From reading this thread sounds like the Viper100a should be the first thing to check.

Thanks.

hi
can you tell me as kindly you have done to find the electric scheme of the power supply?
I am looking for him scheme of the power supply/ballast for Infocus LP730
where I can find him?
thanks

3rd March 2010, 02:15 AM	#73
Gizmotech diyAudio Member Join Date: Mar 2005	99benns and axlp, give us a picture of the PSU (not the ballast). __________________ Projector bulbs, burners, lamps, reflectors and ballasts Last edited by Gizmotech; 3rd March 2010 at 02:18 AM.

17th March 2010, 02:30 AM	#76
Gizmotech diyAudio Member Join Date: Mar 2005	Yep, C16 is the common culprit. Best thing to do is replace it with quality rubycon or panasonic caps then it should be ok for good. __________________ Projector bulbs, burners, lamps, reflectors and ballasts

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2nd March 2010, 12:09 PM	#72
axlp diyAudio Member Join Date: Mar 2010	Hi. I've just been testing the PSU. Looks like the schematic is good based on comparisons i've made so far. I can't see any fried components as others have and also can't see anything shorted on the primary side. Is it still worth replacing the Viper100a? Btw I think power to the ballast is ok as it reads about 380v DC which is what the schematic is saying. Thanks.

6th March 2010, 02:04 PM	#75
axlp diyAudio Member Join Date: Mar 2010	Hi. Quick update. I've managed to get life back into the projector again. For how long who knows! I ended up just changing these 2 components: U2 - VIPer100a C16 - 100uf 16v (swapped with 25v) I think what happens is if the projector is left permanently plugged in the PSU bakes and kills the components. Really one of the fans should be permanently on providing it with air flow. After it shuts down (cools) I think i'll always unplug it. The lamp was only used for 362 hours according to the menu. Hope this helps.

17th March 2010, 12:44 PM	#77
axlp diyAudio Member Join Date: Mar 2010	Yes C16 was the only real problem component I found. I replaced the Viper100a due to the reported failures in other PSUs but the original tested ok. The cap was reading about 75uf so a little on the low side. Also I replaced it with a 105 degrees rated one as the original is only 85 degrees. Given how hot these things can get in standby seems like it should be higher.

22nd April 2010, 02:26 PM	#78
sujatapatil diyAudio Member Join Date: Apr 2010	i have infocus LP350 i