DM500S shows Frontend: Unknown ( tuner fault ) - Page 3

**Fernbay** · 26-03-09, 11:05 AM

Just for you LP, heres a blow by blow

The answer is the 'plug in tuner'

Tested remote (checked OK). Changed IR board twice with new ones - didn't fix it.
Replaced main board with new twice - still didn't fix it
So, that left the tuner

Went over it with a meter on diode test & found the cap C6 was short.
Replaced it & found problem was solved

Quote:

Originally Posted by LeroyPatrol

Sheesh how did you trouble shoot that one? You wouldn't think it would be a cap on the tuner board!

Leroy

**LeroyPatrol** · 26-03-09, 11:41 AM

Ah the plug in tuner. Thanks for that. There's another good reason them.

Leroy

**gw1** · 06-05-09, 11:00 AM

Tuner problems? See also: due to damaged LT1930 chip.

**uutgrunn** · 02-12-09, 08:36 PM

Hi, sorry for my bad english. I also have a DM500s with a faulty tuner.

I saw that the fault could be in capacitor c4 and c6. These are ceramics,
but what are these values?

What else should I check?

If you have more info, you can also e-mail me directly:
dm500nl[atthingy]gmail[dot]com

Thanks in advance!

**mmsuranjith** · 15-12-09, 12:29 AM

Quote:

Originally Posted by Phillip James

Gentlemen,

Thanks for all your help, my first DM500S which showed "Frontend:Unknown" is now repaired, I went throught the tricky process of installing a new ALPS tuner and straight away got "Frontend:Satellite", its scanned OK. Subsequently I installed PLI Iolite and all back to normal.

For my second DM500 which lost its +30v for the varicap tuner, it was a bit more tricky........this supply is generated on the underside of the tuner sub board with a 5 pin unknown IC and inductor etc. Discovered a minimum of +14v is adequate for the varicap supply, did a shonk and installed a 9v battery with negative connected to the incoming +12v Dreambox supply giving +21v and this I connected to pin 5 of the tuner (varicap supply).

When powered up the battery supplies 700uA so it should last a while. Later I will replace the battery with a 555 driving a voltage tripler, but for now I have two working DM500's.

Thanks for all you inspiration.

Regards,

how can i connect 30v in? tuner side pin 5 empty ?

**mmsuranjith** · 15-12-09, 12:37 AM

Quote:

Originally Posted by z80

Thanks for saying thanks.

You did a fantastic job isolating that component to be the fault.

C4 underneath the Alps tuner unfortunately is on the little daughter board.
A lot of unsoldering to get to a nasty little cap...

dear sir ,

can you tell me c4 capacitor value

thank you....

**cwispy** · 18-12-09, 04:20 PM

Quote:

Originally Posted by mmsuranjith

dear sir ,

can you tell me c4 capacitor value

thank you....

Use about a 1uf 50v ceramic. Its not that critical its the exact same value that was on there.

**ozfox** · 26-12-09, 11:08 AM

Hi all,

There is some great reading in this thread on fault finding, thank you all for the info.

Is anyone able to advise the part value of the diode D2. It is located on the underside of the tuner card BSBEI-703A.

Thank you

**limit** · 05-01-10, 01:48 AM

hi.....i have similar problems but i dont know where to start.......

when i check in dreambox in i can see Frontend:Satellite

but any how i cant tune on any channels......when i try to scan box finds only 1 transponder maybe 8 channels only ......but still no picture i get on them.....

Also i notice tuner temperature is hot .......i guess there's a short on it same where ......??????

how i can repair pls....??????where to start???

many thanks...

**limit** · 05-01-10, 09:01 PM

sorry i make a wrong post can mod's delete this ..thanks

**LeroyPatrol** · 05-01-10, 09:13 PM

why not pm fernbay and buy another tuner?

**dorcky** · 08-01-10, 03:14 AM

Quote:

Originally Posted by z80

oh alright, here you go......

Hello, everyone, I want to ask if anyone of you have the rest of the schematic for DM500 witch is equipped whit tuner like in the picture from above picture. Thank You!

**limit** · 15-01-10, 07:43 PM

Quote:

Went over it with a meter on diode test & found the cap C6 was short.
Replaced it & found problem was solved

hi..can you pls tell us the value of the C6......????thanks

**sanjin** · 05-02-10, 10:12 AM

Quote:

Originally Posted by Phillip James

My genuine Dreambox DM500S with ALPS tuner and running Dream release 4.2.0 17.12.2007 is not working.

If I select "INFO>About", it says Frontend: Unknown.

I have tried flashing various images and allways Frontend: Unknown.

What do I do?

Regards,

try connecting another dvb-s receiver thru loop f-connector on dm500.pick on both the same transponder.check if both works and deliver picture,if so,then is faulty a smd mosfet in dc 30v step-up converter on main board.do not use multimeter.just replace mosfet.if you get the picture nothing wrong with tuner and sub board.

**sidplayos2** · 15-02-10, 05:47 PM

I need to replace the c725 cap but not sure what value or type it is. I tested with a 220uF/25v and the tuner works again, however I would like to replace with the correct component if possible.

I noticed on the schematic it mentions c725 = 475, and from my research on the net of smd codes the first 2 digits are the cap value, and the last digit the multiplier in pF.

So 47 x 10^5 pF = 4.7uF. Can anyone confirm I'm on the right track here? Also what would be the type of cap to use, tantalum, ceramic, electro etc?

Cheers

**cwispy** · 15-02-10, 07:02 PM

Just checked an old board here and it is a 4.7uf ceramic.

**sidplayos2** · 16-02-10, 10:02 AM

Thanks cwispy, works great.

Quote:

Originally Posted by cwispy

Just checked an old board here and it is a 4.7uf ceramic.

02-12-09, 08:36 PM	#44
uutgrunn Junior Member Join Date: Dec 2009 Posts: 1 Gameroom cash: $510 Thanks: 0 Thanked 0 Times in 0 Posts Rep Power: 0	Hi, sorry for my bad english. I also have a DM500s with a faulty tuner. I saw that the fault could be in capacitor c4 and c6. These are ceramics, but what are these values? What else should I check? If you have more info, you can also e-mail me directly: dm500nl[atthingy]gmail[dot]com Thanks in advance! Last edited by uutgrunn; 02-12-09 at 08:47 PM. Reason: wrong email

26-12-09, 11:08 AM	#48
ozfox Junior Member Join Date: May 2008 Posts: 1 Gameroom cash: $805 Thanks: 0 Thanked 0 Times in 0 Posts Rep Power: 0	DM 500s tuner fault Hi all, There is some great reading in this thread on fault finding, thank you all for the info. Is anyone able to advise the part value of the diode D2. It is located on the underside of the tuner card BSBEI-703A. Thank you

05-01-10, 01:48 AM	#49
limit Junior Member Join Date: Jun 2009 Posts: 13 Gameroom cash: $770 Thanks: 0 Thanked 0 Times in 0 Posts Rep Power: 0	hi.....i have similar problems but i dont know where to start....... when i check in dreambox in i can see Frontend:Satellite but any how i cant tune on any channels......when i try to scan box finds only 1 transponder maybe 8 channels only ......but still no picture i get on them..... Also i notice tuner temperature is hot .......i guess there's a short on it same where ......?????? how i can repair pls....??????where to start??? many thanks... Last edited by limit; 05-01-10 at 10:07 PM.

05-01-10, 09:01 PM	#50
limit Junior Member Join Date: Jun 2009 Posts: 13 Gameroom cash: $770 Thanks: 0 Thanked 0 Times in 0 Posts Rep Power: 0	sorry i make a wrong post can mod's delete this ..thanks Last edited by limit; 05-01-10 at 10:08 PM.

05-01-10, 09:13 PM	#51
LeroyPatrol Premium Member Join Date: Jan 2008 Location: N.E. Vic Posts: 5,226 Gameroom cash: $5396 Thanks: 92 Thanked 435 Times in 262 Posts Rep Power: 120	why not pm fernbay and buy another tuner? __________________ MEDIASTAR HD 1100S PVR / HDX 9100 PVR- $299 / $449 Update your old Aurora box to a HD PVR today Selectv Sub Cards - $39 or $29 for Premium Members inc. post with 1 month FREE!

26-03-09, 11:41 AM	#42
LeroyPatrol Premium Member Join Date: Jan 2008 Location: N.E. Vic Posts: 5,226 Gameroom cash: $5396 Thanks: 92 Thanked 435 Times in 262 Posts Rep Power: 120	Ah the plug in tuner. Thanks for that. There's another good reason them. Leroy

06-05-09, 11:00 AM	#43
gw1 Senior Member Join Date: Jan 2008 Location: Hobart Posts: 958 Gameroom cash: $3331 Thanks: 49 Thanked 587 Times in 208 Posts Rep Power: 39	Tuner problems? See also: due to damaged LT1930 chip.

15-02-10, 05:47 PM	#55
sidplayos2 Junior Member Join Date: Mar 2008 Posts: 3 Gameroom cash: $850 Thanks: 0 Thanked 0 Times in 0 Posts Rep Power: 0	I need to replace the c725 cap but not sure what value or type it is. I tested with a 220uF/25v and the tuner works again, however I would like to replace with the correct component if possible. I noticed on the schematic it mentions c725 = 475, and from my research on the net of smd codes the first 2 digits are the cap value, and the last digit the multiplier in pF. So 47 x 10^5 pF = 4.7uF. Can anyone confirm I'm on the right track here? Also what would be the type of cap to use, tantalum, ceramic, electro etc? Cheers

15-02-10, 07:02 PM	#56
cwispy Senior Member Join Date: Jan 2008 Posts: 910 Gameroom cash: $2347 Thanks: 24 Thanked 42 Times in 31 Posts Rep Power: 22	Just checked an old board here and it is a 4.7uf ceramic. __________________ Scart to component cables now in stock http://www.ausmodchips.com.au Wii, Xbox, Xbox 360, PS2, PS3 mods, accessories and repairs. http://www.ausmodchips.com Xbox 360 RRoD and PS3 repair service

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