[TechAssist] Re: Another CTC187CN3 regulator and HOT running hot
- From: "al m" <ampm@xxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Sat, 14 Aug 2004 09:31:47 -0400
Gary I have something marked on my print but I'm not at the shop now. I
think it had something to do with the -15 volt filter. I'll check it out and
get back to you.
Al Marquardt
ampm@xxxxxxx
Al Marquardt Electronic Repair
206 W Main
Girardville Pa. 17935
----- Original Message -----
From: "Gary McCartney" <gary@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Saturday, August 14, 2004 3:03 AM
Subject: [TechAssist] Another CTC187CN3 regulator and HOT running hot
> I have a 31" GE TV with chassis CTC187CN3. Set came in with regulator,
> HOT, CR4106 and fuse all bad.
>
> I used a generic STK730-150 (same as # on original) and an OEM 223942
> (BUH517) for the HOT. For the CR4106, I used a generic MR856, which has
> faster switching time than the original PFR856.
>
> Fired set up and it ran but after an hour the HOT heatsink was at 60
> deg. C and the reg. heatsink was at 70 deg. C. B+ on cathode of CR4106
> is 146V with set off and 139.2V with set on.
>
> Since then, I have changed the following parts, all OEM unless otherwise
> noted:
>
> - 215541 hor driver transformer
> - 188594 cap, C4306
> - 175374 22 ohm resistor , R4402
> - 214753 cap, C4403
> - 206008 cap, C4402
> - 242907 CR4402 damper
> - 176296 CR4303 diode
> - 218492 cap, C4407
> - CR4403 - used MR856 as sub to PFR856 164589
> - C4105 cap 10 uF 200V generic
> - C4709 47uF 35V generic
> - R4126 30K 3W resistor generic
> - CR4109 7.5V 1W zener diode generic
>
> also checked C4107 for ESR and value, checked ok. Tried a 2SD1886 for
> the HOT as well as a second OEM 223942 BUH517, from the same lot as
> first one. No temp differences except the 2SD1886 ran hotter if anything.
>
> With all these parts changed, I see very little improvement if any in
> the heat situation. The picture looks absolutely fine, no bowing,
> shrinkage, or anything.
>
> I added extra heatsinks to the REG. and HOT. This has brought the REG
> temp down to 60 deg. C and the HOT temp down to 40 deg. C. I'd still
> like to know what can be causing these temperature problems. I'm sure
> I've had CTC187's in here that ran much cooler than this. A few months
> ago I had another one running hot. Had same problems trying to cool it
> down so I installed heatsinks. Brought the temp down just like this set
> and I've never heard back from the customer.
>
> Any ideas to suggest? an OEM STK730-150 is way too expensive but is that
> the answer? I asked other members who buy from my supplier (Global) if
> they used those generic STK's and they all said "all the time, no
> problem" What about the HOT heat? Flyback? Maybe but that other set I
> had, I did replace the flyback and it still had the same problem as this
> set.
>
> Thanks for any help. Sorry the message so long.
>
>
>
>
>
>
> Gary McCartney
>
> McCartney Electronics
> Guelph Ontario Canada
> Est. 1984
> email: gary (at) number63.ca
>
>
>
>
>
>
>
>
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