[TechAssist] Re: Power MOSFET - Huge Flash
- From: "Paul Westcott" <westcott@xxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Fri, 29 Jul 2005 14:33:16 -0400
Bil,
Different chassis use different values.
Paul Westcott
Kingsway Electronics
1090 Kingsway
Sudbury, Ontario
Canada
Phone 705 566-9290
Fax 705 566-5349
westcott@xxxxxxx
----- Original Message -----
From: "Bil Green" <tv.vcrrepair@xxxxxxxxxxx>
To: "Paul Westcott" <westcott@xxxxxxx>
Cc: <techassist@xxxxxxxxxxxxx>
Sent: Friday, July 29, 2005 1:28 PM
Subject: [TechAssist] Re: Power MOSFET - Huge Flash
> Hi Paul,
>
> Thanks. I checked the original resistors (one was marked 360k,
> not 380k) and these 2 checked OK before the transistor blew out
> again. Is there supposed to be a 380k also? (maybe I missed that
> one).
>
> Bil
>
> PC 1000
> M-Pulse 5000 magnetic pulse generator
> http://magpulser.com
> Mammoth Lakes, CA
> 760-924-1000
>
>
>
> Friday, July 29, 2005, 6:20:37 AM, you wrote:
>
> PW> Bil,
> PW> Check for an open R14146 (380 k) or R14145 (270 k)
> PW> If these are bad, the MOSFET will literally explode when the set is
plugged
> PW> in.
> PW> HTH
> PW> Paul Westcott
> PW> Kingsway Electronics
> PW> 1090 Kingsway
> PW> Sudbury, Ontario
> PW> Canada
> PW> Phone 705 566-9290
> PW> Fax 705 566-5349
> PW> westcott@xxxxxxx
> PW> ----- Original Message -----
> PW> From: "Bil Green" <tv.vcrrepair@xxxxxxxxxxx>
> PW> To: ".TECHASSIST @ freelists . org" <techassist@xxxxxxxxxxxxx>
> PW> Sent: Friday, July 29, 2005 4:30 AM
> PW> Subject: [TechAssist] Power MOSFET - Huge Flash
>
>
> >> I replaced a shorted MOSFET (driver in SMPS) and other parts
> >> (listed below) and as soon as the set was plugged in there was a
> >> huge flash (arcing) observed at the MOSFET and it shorted
> >> immediately.
> >>
> >> There is carbon between the metal clip and the plastic front (not
> >> the backside, and there is no crack visible in the plastic) of
> >> the MOSFET. I don't want to power it up again until I have a clue
> >> as to what is likely causing this (the original one didn't do
> >> this).
> >>
> >> I did use a TDA4605-2 (instead of -3) for U14101, and I can't
> >> imagine this caused enough voltage (thousands?) to create this
> >> large arc.
> >>
> >> With less AC voltage the set probably won't start so I rather not
> >> use this method.
> >>
> >> RCA PTV
> >> model P61929
> >> chassis PTK195ST
> >>
> >> Q101 (MOSFET) shorted
> >> U14101 melted
> >> R14125 burned
> >>
> >> Replaced 3 other resistors as recommended (checked OK)
> >>
> >> Bil
> >>
> >> PC 1000
> >> M-Pulse 5000 magnetic pulse generator
> >> http://magpulser.com
> >> Mammoth Lakes, CA
> >> 760-924-1000
> >>
>
>> -------------------------------------------------------------------------
-
> PW> ---
> >> This Email List is Public. Remove:
http://www.tech-assist.org/remove.htm
> >> Set Vacation
> PW> mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
> >> Lost Password: http://www.tech-assist.org and select "Login
Problems?".
> >> Email Archives: //www.freelists.org/archives/techassist/
> >>
>
>
PW> ------------------------------------------------------------------------
-----
> PW> This Email List is Public. Remove:
http://www.tech-assist.org/remove.htm
> PW> Set Vacation
mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
> PW> Lost Password: http://www.tech-assist.org and select "Login
Problems?".
> PW> Email Archives: //www.freelists.org/archives/techassist/
>
> --------------------------------------------------------------------------
---
> This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
> Set Vacation
mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
> Lost Password: http://www.tech-assist.org and select "Login Problems?".
> Email Archives: //www.freelists.org/archives/techassist/
>
-----------------------------------------------------------------------------
This Email List is Public. Remove: http://www.tech-assist.org/remove.htm
Set Vacation mailto:ecartis@xxxxxxxxxxxxx?subject=set%20techassist%20vacation
Lost Password: http://www.tech-assist.org and select "Login Problems?".
Email Archives: //www.freelists.org/archives/techassist/
Other related posts:
