M542 problems see pictures

[ciaranconlon]

hi guys

wee problem, was careful wiring up my M542 to my breakout broad that the mix up the + an - for the 24v supply and BOOOOM.

opened it up and this is the result

http://sphotos-f.ak.fbcdn.net/hphoto...11688174_n.jpg (http://sphotos-f.ak.fbcdn.net/hphotos-ak-snc7/299045_499936803362221_411688174_n.jpg)

i no how stupid of me.

now i open one another one and this is wat is missing

http://sphotos-e.ak.fbcdn.net/hphoto...01523726_n.jpg (http://sphotos-e.ak.fbcdn.net/hphotos-ak-prn1/68651_499936766695558_1901523726_n.jpg)

can anyone tell me what it is???? the code on it is 1051 RV done a google serach but got nothing.

http://sphotos-d.ak.fbcdn.net/hphoto...86732269_n.jpg (http://sphotos-d.ak.fbcdn.net/hphotos-ak-snc6/215774_499936816695553_1586732269_n.jpg)

thanks guys

[wilfy]

its a surface mount 1.05kohm resistor

however i wouldnt like to say if just replacing that will make everything alright

[Jonathan]

I reckon it's a diode since there's a stripe. You'll be lucky if replacing it solves the problem. I guess you could de-solder the good one from the working driver and test it for free...

[dsc]

Me also thinks it's a diode, probably there to stop you from blowing the board up with what you've managed to do (swapping voltage pos and neg). Since re/de-soldering anything from surface mounts can be a bit tricky, I'd suggest getting a replacement from somewhere (you can always contact the manufacturer to check for the model and package no) and leaving the good board in peace.

Regards,
dsc.

[i2i]

it looks like a diode to me as well, put there to short the supply if you connect it wrong. If so you should be able to run the drive without it there, have you tried it.?

[Ricardoco]

it looks like a diode to me as well, put there to short the supply if you connect it wrong. If so you should be able to run the drive without it there, have you tried it.? It reminds me of the old CB radios that had a reverse polarity diode on the back to protect the board, but more often then not it used to blow the output transistor on the final stage as well anyhow.. Rick

[i2i]

i've replaced so many of those i've lost count, sometimes the audio chip would take a beating but i don't remember the rf output failing from that.

General electric made their cb radios with the supply connection the same as the standard uniden chasssis but with the supply reversed (that made me a fair bit of cash) especially when they were told to replace the power lead and didn't bother.

the good old days eh!

[i2i]

if the diode was put in series with the supply and the device on one lead, it would protect it far better but there would be a small voltage drop across the diode.

[Ricardoco]

i've replaced so many of those i've lost count, sometimes the audio chip would take a beating but i don't remember the rf output failing from that.

General electric made their cb radios with the supply connection the same as the standard uniden chasssis but with the supply reversed (that made me a fair bit of cash) especially when they were told to replace the power lead and didn't bother.

the good old days eh! Yep you are right, they used to come in with a really quiet hiss from the speaker, the brain is letting me down.. I used to replace a lot of RF outputs on the sets that the SWR was run high and the screwdriver gang had tweaked of the end of the scale LOL... Yep the good old days... easy money too putting the extra channels in with the 10kc shift (ver-icap to 10.240) LOL yep them were the days...LOL Rick

[Swarfing]

Get off the the cybernet boards and phase lock loops you old gits and flipflop back to work before i wack your BREMI :hysterical:

[wilfy]

thinking about it there is an easy way to test if it's a resistor or a diode and that is using the diode test on a multi meter, one way it will read, the other way it wont.

[i2i]

Get off the the cybernet boards and phase lock loops you old gits and flipflop back to work before i wack your BREMI :hysterical:my god, bremi power supplies. very good at the time especially when altai was the driving force in cheap electronics.

[Swarfing]

Back then they were better known for what was called burners (boots) CQ italia

[Swarfing]

Getting back to the task in hand, i had one (different model) that i acquired blown. It would not power up without the diode in place. This one could be different?

[i2i]

Back then they were better known for what was called burners (boots) CQ italiayes they made burners, personally i sold so many power supplies made by them it sticks in my mind. Years ago i used to wholesale cb equipment.

PS. they had a very low failure rate compared to other brands.

[i2i]

Getting back to the task in hand, i had one (different model) that i acquired blown. It would not power up without the diode in place. This one could be different?if the diode is in series with the power lead it needs to be there to conect the circuit, but this one looks like it's across the supply.

[Swarfing]

Here was my thread

http://www.mycncuk.com/forums/drivers-controllers/4710-m542-driver.html

[m_c]

Going by the component number (TV1), I'd guess it's a TVS diode.
Protects against overvoltage and reverse polarity, and leaves visible evidence if the feed isn't protected by a suitable fuse.

I'd hazard a guess that the 51 part of the number on it relates to the voltage it's meant to conduct, and the 10 relates to the size.
If you can figure out he SMD pad size, have a search on RS or Farnell for something suitable.

[Swarfing]

Look up this part number SMAJ48A-TR from RS, it will put you in the right ball park