[TechAssist] Re: Philips HOT BU2508DF Mis-labeled
- From: "LeRoy Westlund" <llw@xxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Fri, 2 Apr 2004 23:15:47 -0700
Oh,...Oh !!!!!!!
;-)
LLW
LeRoy Westlund
Westlund TV & Electronics
97 North Main "Where there's a will,...
Centerfield, UT 84622-0087 There's always a way."
Ph./Fax 435-528-3822
mailto:LLW@xxxxxxxxxx
-----Original Message-----
From: becyn <becyn@xxxxxxxxxx>
To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
Date: Thursday, April 01, 2004 3:04 PM
Subject: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>Nesdanet? Is Nesda still in business? If so, what have they done for you
>lately?
>
>Jim McVey
>McVey Alltronix
>327 Broadway
>Newburgh Ny 12550
>ph: 845 561 8383
>fx: 845 561 9017
>Consumer electronics &
>computer service.
>Factory authorized for
>over twenty brands.
>----- Original Message -----
>From: "J Silverman" <greentron@xxxxxxx>
>To: "Intrepid Video Support" <support@xxxxxxxxxxxxxxxxxx>;
><techassist@xxxxxxxxxxxxx>
>Sent: Thursday, April 01, 2004 2:19 PM
>Subject: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>
>
>> I cant argue with you as I rarely make such a measurement. I am just
>> forwarding information that techs have posted on Nesdanet in the past
>> concerning this problem.
>> Jerry Silverman
>> Greentron Inc
>> 4 Newland Ave
>> Greenville SC 29609
>> 864 232 3889
>> Fax 271 2080
>> mailto:greentron@xxxxxxx
>> ----- Original Message -----
>> From: "Intrepid Video Support" <support@xxxxxxxxxxxxxxxxxx>
>> To: "J Silverman" <greentron@xxxxxxx>; <techassist@xxxxxxxxxxxxx>
>> Sent: Wednesday, March 31, 2004 6:00 PM
>> Subject: Re: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>>
>>
>> > Then you need a new ohm meter...
>> > I don't think I have ever seen a HOT with lower than 50 ohms.
>> >
>> > Jeff Dougherty
>> > Intrepid Video TV/VCR
>> > 263 S Front St
>> > Steelton PA 17113
>> > fax...717-564-4952
>> > www.intrepid-video.com www.tech-repair.net
>> >
>> > ----- Original Message -----
>> > From: "J Silverman" <greentron@xxxxxxx>
>> > To: "Intrepid Video Support" <support@xxxxxxxxxxxxxxxxxx>;
>> <techassist@xxxxxxxxxxxxx>
>> > Sent: Wednesday, March 31, 2004 3:59 PM
>> > Subject: Re: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>> >
>> >
>> > I never heard of a "too low" resistance complaint. Complaint was always
>> that
>> > the resistance was too high. On some HOTs the normal level is about 25
>> ohms.
>> > Jerry Silverman
>> > Greentron Inc
>> > 4 Newland Ave
>> > Greenville SC 29609
>> > 864 232 3889
>> > Fax 271 2080
>> > mailto:greentron@xxxxxxx
>> > ----- Original Message -----
>> > From: "Intrepid Video Support" <support@xxxxxxxxxxxxxxxxxx>
>> > To: <techassist@xxxxxxxxxxxxx>; <greentron@xxxxxxx>
>> > Sent: Wednesday, March 31, 2004 9:57 AM
>> > Subject: Re: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>> >
>> >
>> > > If the resistance is too low, same thing.
>> > > Ideal resistance should be in the 60-70 ohm range.
>> > >
>> > > Jeff Dougherty
>> > > Intrepid Video TV/VCR
>> > > 263 S Front St
>> > > Steelton PA 17113
>> > > fax...717-564-4952
>> > > www.intrepid-video.com www.tech-repair.net
>> > >
>> > > ----- Original Message -----
>> > > From: <greentron@xxxxxxx>
>> > > To: <techassist@xxxxxxxxxxxxx>
>> > > Cc: "Corey Brazell" <cohbraz@xxxxxxxxxxxxxx>;
><techassist@xxxxxxxxxxxxx>
>> > > Sent: Tuesday, March 30, 2004 10:42 PM
>> > > Subject: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>> > >
>> > >
>> > > Those are counterfeit. Regardless of what other differences there
are,
>> > they will burn out quickly without
>> > > the resistor. The resistor damps parasitic oscillations and has to be
>as
>> > close to the junction as
>> > > possible, which is why they are fabricated internally. No distributor
>> > intentionally ships counterfeits but
>> > > we hear about this thing all the time. Some techs keep a list of the
>> > resistor measurement for a given type
>> > > of hot and check all of the new stock against the list. If the
>resistor
>> > value is more than 20% above the
>> > > nominal value, they know from experience that the hot wont last.
>> > > J Silverman
>> > >
>> > >
>> > > > That's what it said on PartSeeker, but when I ordered it, it subbed
>to
>> > that
>> > > > BU2508DF.
>> > > >
>> > > > Regardless, any BU2508DF should have the dampening diode and
biasing
>> > > > resistor; I have several older BU2508DF that do and read 40 ohms.
>But,
>> > > > these new ones that I ordered that all have the same date code not
>> have
>> > > > that resistor. There is around a 2 Meg Ohm resistance between Base
>and
>> > > > Emitter.
>> > > >
>> > > > So, I have two different BU2508DF transistors. Older ones that are
>> > correct,
>> > > > and newer ones that do not have the biasing resistor.
>> > > >
>> > > > Also, I just noticed that the new DF's don't look the same as the
>> older
>> > > > ones. It looks like they have been re-stamped. The front of these
>look
>> > as
>> > > > if they have been fine-sanded to a smooth even surface and then
>> stamped.
>> > My
>> > > > older DF's Have three round indentions on the front face. One in
the
>> > middle
>> > > > near the bottom, and two toward the top near each side. These new
>ones
>> > are
>> > > > smooth all the way across. As a matter of fact, I have one that is
>> > stamped
>> > > > on both sides!
>> > > >
>> > > > Corey Brazell
>> > > > Audio Video Electronics
>> > > > 12169 SC Hwy 121
>> > > > Newberry SC 29108
>> > > >
>> > > >
>> > > > > [Original Message]
>> > > > > From: Intrepid Video Support <support@xxxxxxxxxxxxxxxxxx>
>> > > > > To: <techassist@xxxxxxxxxxxxx>
>> > > > > Date: 3/30/2004 3:29:48 PM
>> > > > > Subject: [TechAssist] Re: Philips HOT BU2508DF Mis-labeled
>> > > > >
>> > > > > Corey,
>> > > > > Thanks for the information, but that part number is for Philips
>> S2055,
>> > > > 610597
>> > > > >
>> > > > > Jeff Dougherty
>> > > > > Intrepid Video TV/VCR
>> > > > > 263 S Front St
>> > > > > Steelton PA 17113
>> > > > > fax...717-564-4952
>> > > > > www.intrepid-video.com www.tech-repair.net
>> > > > >
>> > > > > ----- Original Message -----
>> > > > > From: "Corey Brazell" <cohbraz@xxxxxxxxxxxxxx>
>> > > > > To: <techassist@xxxxxxxxxxxxx>
>> > > > > Sent: Tuesday, March 30, 2004 1:07 PM
>> > > > > Subject: [TechAssist] Philips HOT BU2508DF Mis-labeled
>> > > > >
>> > > > >
>> > > > > I have received two separate shipments of these BU2508DF
>transistors
>> > from
>> > > > > Philips, and the transistors do not have the built-in
Base-Emitter
>> > bias
>> > > > > resistor. They seem to be a BU2508AF. The transistors in both
>> > shipments
>> > > > > have the same date code: 0231 C2
>> > > > >
>> > > > > Philips is now running a Stock Check on these parts. They may
also
>> be
>> > > > under
>> > > > > part number 4835 130 47897.
>> > > > >
>> > > > > If you have any of these type HOTs, check them!
>> > > > >
>> > > > >
>> > > > > Corey Brazell
>> > > > > Audio Video Electronics
>> > > > > 12169 SC Hwy 121
>> > > > > Newberry SC 29108
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > > > >
>> > >
>> >
>>
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