[TechAssist] Re: Mitsubishi PTV VS45501A No video to blue CRT
- From: "LeRoy Westlund" <llw@xxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Wed, 15 Jan 2003 01:31:24 -0700
The Q222 ckt. is OK.
I went over it with a fine tooth comb.
Maybe I'll have to find the exact manual, before I can continue any further.
I'm having problems buying Mits parts, or I wouldn't have bothered the list
so much about this problem. I think there is a limit to how much a guy can
help another tech over an e-mail list. We may have reached that limit. If I
had the correct service manual to start with, I probably would have found
the problem by now.
Thanks for your help, Demon.
Keep in touch, if you get anymore ideas.
LLW
LeRoy Westlund
Westlund TV & Electronics " Walk tall,...Walk straight
93 North Main and look the world
Centerfield, UT 84622-0087 right in the eye "
Ph./Fax 435-528-3822
mailto:LLW@xxxxxxxxxx
-----Original Message-----
From: Damon <DAMON101@xxxxxxxxxxxxxx>
To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
Date: Tuesday, January 14, 2003 7:33 PM
Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue CRT
>
>Darn, that means my schematics are incorrect. Pin 8 (Blue gain) measures
>good, Pin 17 (DC adjust) affects all 3 outputs and Pins 1 thru 7 operate a
>"Linear white" block which is connected to Blue output only.....thru a
built
>in "adder circuit". Wonder if that "Linear White is actually a DAC, cuz the
>inputs are labeled A1 A2 A3 and B1 B2 B3. Anyways, Q2H12 voltage does seem
>to be a bit higher than what the schems say it should be, 2.4V on base,
3.0V
>on emitter.
>
>Q222 does have another zener tied to the emitter....D226 which is an
>HZ-3BLL. Emitter has 2.75V and base is 3.1V, wonder if that could have an
>effect on Q2H12??
>
>Damon Brunger
>damon101@xxxxxxxxxxxxxx
>Telrad Electronic Services
>Ft Wayne, IN 46815
>
>----- Original Message -----
>From: "LeRoy Westlund" <llw@xxxxxxxxxx>
>To: <techassist@xxxxxxxxxxxxx>
>Sent: Tuesday, January 14, 2003 3:01 PM
>Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue CRT
>
>
>>
>> Damon,
>> Those resistor values are not correct.
>> R2H02 is 3.9K ohms, and R2H24 is 1.6K.
>> R2H29, and R2H28 measure the same, also, respectfully.
>> Color codes match OK on all 4 of them, with the values I measured.
>>
>> Regards,
>> LLW
>>
>> LeRoy Westlund
>> Westlund TV & Electronics " Walk tall,...Walk straight
>> 93 North Main and look the world
>> Centerfield, UT 84622-0087 right in the eye "
>> Ph./Fax 435-528-3822
>> mailto:LLW@xxxxxxxxxx
>>
>> -----Original Message-----
>> From: Damon <DAMON101@xxxxxxxxxxxxxx>
>> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
>> Cc: LLW@xxxxxxxxxx <LLW@xxxxxxxxxx>
>> Date: Tuesday, January 14, 2003 6:42 AM
>> Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue CRT
>>
>>
>> >
>> >Pin 2 of IC 204 should have 0.9V on it and that voltage comes from a
>> voltage
>> >divider connected to 12V....R2H02 is 16K ohm connected to 12V and R2H24
>is
>> >1.5K ohm connected to ground, I think your R2H24 has changed value. Pin
3
>> is
>> >a little low, should be 4.2V check R2H03 5.6K ohm and R2H25 3.3K ohm.
>> >Pin 6 is too high, should be 0.9V too. Check R2H29 16K ohm, and R2H28
>1.5
>> >Kohm.
>> >
>> >
>> >----- Original Message -----
>> >From: "LeRoy Westlund" <llw@xxxxxxxxxx>
>> >To: <techassist@xxxxxxxxxxxxx>
>> >Sent: Monday, January 13, 2003 1:15 PM
>> >Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue CRT
>> >
>> >
>> >>
>> >> Damon,
>> >> Thanks, we are making progress !
>> >> Please bare with me, just a little longer.
>> >> I replaced the Zener D227 with another 5.1 volt zener.
>> >> The bias on Q2H12 changed to 3.60- base, 4.08-emmiter, and
>.02-Collector.
>> >> The video is now coming through, but, the blue CRT is now too bright.
>> >> I can't turn the blue screen control down very far, or I lose video. I
>> >have
>> >> to leave it in about the center range. (I already have replaced the
>> >> Focus/Screen block on this set).I am thinking that I still need to get
>> the
>> >> voltage lower on Q2H12- base. Maybe my zener is still not a good
enough
>> >> substitute. I will try a lower value.
>> >> The voltages on IC204 are:
>> >> 1- 4.92
>> >> 2- 3.31
>> >> 3- 3.72
>> >> 4- 5.05
>> >> 5- 11.32
>> >> 6- 3.31
>> >> 7- 3.71
>> >> 8- 7.62
>> >> 9- 4.97
>> >> 10- 3.61
>> >> 11- 6.32
>> >> 12- 6.69
>> >> 13- 6.64
>> >> 14- .35
>> >> 15- 5.64
>> >> 16- .02
>> >> 17- 2.29
>> >> 18- 3.92
>> >> 19- 4.41
>> >> 20- 3.61
>> >>
>> >> Regards,
>> >> LLW
>> >>
>> >> LeRoy Westlund
>> >> Westlund TV & Electronics " Walk tall,...Walk straight
>> >> 93 North Main and look the world
>> >> Centerfield, UT 84622-0087 right in the eye "
>> >> Ph./Fax 435-528-3822
>> >> mailto:LLW@xxxxxxxxxx
>> >>
>> >> -----Original Message-----
>> >> From: Damon <DAMON101@xxxxxxxxxxxxxx>
>> >> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
>> >> Date: Monday, January 13, 2003 6:17 AM
>> >> Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue CRT
>> >>
>> >>
>> >> >
>> >> >Q2H12 emitter is B+ supply side of PNP...and also signal out. 5.3
>Volts
>> >on
>> >> >base is too Hi, should be 2.7V from Pin 20 thru r2h47 100 ohm to
base,
>> >> r2h46
>> >> >on emitter is 1800 ohm and connects to 12V supply.
>> >> >
>> >> >Also look at IC204, Pin 8, known as B-gain, should be 7.8V (resistors
>> >R2h04
>> >> >8200 ohm and R2h06 20kohm divide the 12V down to this).
>> >> > Pin 11 Blue input should have 6V (signal is cap coupled into
this)
>,
>> >> >Pin 14 Clamp should have 0 V, Pin 17 DC adj should have 2.3V, Pin 5
is
>> >12V
>> >> >B+ and Pin 16 is Gnd.
>> >> >
>> >> >Pins 1-4 and 6/7 look like they're set to specific voltages: Pin 1 -
>> >4.8v,
>> >> >2- 0.9v, 3- 4.2V, 4 - 4.9V, 6 - 0.9V and 7 is 3.8V. Labeled A1 A2
>A3,
>> >B1
>> >> >B2 B3 from 1 to 7 (address 101 and 101??). This is gamma correction
>IC,
>> >> sure
>> >> >can't remember what gamma correction is tho'
>> >> >
>> >> >I think I saw this problem before, and you may be inclined to replace
>IC
>> >> >204, but check the voltages before replacing it.
>> >> >Damon Brunger
>> >> >damon101@xxxxxxxxxxxxxx
>> >> >----- Original Message -----
>> >> >From: "LeRoy Westlund" <llw@xxxxxxxxxx>
>> >> >To: <techassist@xxxxxxxxxxxxx>
>> >> >Sent: Sunday, January 12, 2003 9:40 PM
>> >> >Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue
CRT
>> >> >
>> >> >
>> >> >>
>> >> >> Damon,
>> >> >> You got me in the right area.
>> >> >> I have video out of IC204-20, to base of Q2H12. That's where I lose
>> it.
>> >> >> Nothing on emitter of Q2H12. Q2H12 is good, but seems to be biased
>> >wrong.
>> >> >> It has 5.3 volts on the Base, 4.7 volts on the emitter, and .02
>volts
>> >on
>> >> >the
>> >> >> collector.
>> >> >>
>> >> >> Is D227 a 5.0, or a 5.1 volt zener ? ( I tried a 5.1, but not sure
>it
>> >was
>> >> >a
>> >> >> good replacement ). No help.
>> >> >> Also,....what is the value of R2C3, and R2A5 ? ( I measure 330 ohms
>> for
>> >> >> R2C3, and 182 ohms for R2A5 ).
>> >> >>
>> >> >> Thanks,
>> >> >> LLW
>> >> >>
>> >> >> LeRoy Westlund
>> >> >> Westlund TV & Electronics " Walk tall,...Walk straight
>> >> >> 93 North Main and look the world
>> >> >> Centerfield, UT 84622-0087 right in the eye "
>> >> >> Ph./Fax 435-528-3822
>> >> >> mailto:LLW@xxxxxxxxxx
>> >> >>
>> >> >> -----Original Message-----
>> >> >> From: Damon <DAMON101@xxxxxxxxxxxxxx>
>> >> >> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
>> >> >> Date: Sunday, January 12, 2003 5:45 AM
>> >> >> Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue
>CRT
>> >> >>
>> >> >>
>> >> >> >
>> >> >> >That's a 1997 VZ4 chassis, you'll find any manual sporting the 97
>VZ4
>> >to
>> >> >be
>> >> >> >of help to you.
>> >> >> >TS50611, VS50502, vs55601, Vs60621.......OH LOOK! I have that
>manual.
>> >> (Ah
>> >> >> >yes carry one manual, work on 7 different units). Let's see.....
>> >> >> >
>> >> >> >Q222 is biassed by a 2.76V zener/resistor combo r2c4 is 390 ohm
>> ,zener
>> >> is
>> >> >> >d226 (hz-3bll) (sorry about bad grammer, lotsa info...). you need
>> 3.1v
>> >> on
>> >> >> >base to drive it. Blue actually has a D227/R2c4 combo on it
>> >> >> >HZ-5cll/F-200....must be a 200 ohm 1/4w.
>> >> >> >
>> >> >> >The base is driven by Q2H12 emitter, PNP 2sa1115, 3V on emitter,
>2.4V
>> >on
>> >> >> >bbase.
>> >> >> >IC204 Pin 20 drives Q2H12. Blue input is Pin 11 of IC204 ----The
>> >above
>> >> >> >circuits are Driven by 12V from RS pin 9.
>> >> >> >
>> >> >> >The next section is....well....weird. 2 transistors, emitters tied
>> >> >> together,
>> >> >> >one transistor is coupled to a bias arrangement that connects
RGB's
>> >2nd
>> >> >> >transistor all at the same point.(Must be a current amp/current
>> >mirror)
>> >> >> .The
>> >> >> >other transistor is for the signal, and that signal ORIGINATES
FROM
>> >> IC200
>> >> >> >PIN 24>>NOTICE I USE BIG LETTERS TO ACCENTUATE YOUR 1ST TEST
>POINT<<
>> >> >Ok,
>> >> >> >lets list the test points from IC200 pin24 to RM 3....
>> >> >> >
>> >> >> >Pin24 to Q2H04 base-emitter to IC204 pin 11. IC204 Pin 20 to Q2H12
>> >> >> >base-emitter to Q222 base-emitter.
>> >> >> >
>> >> >> >Also, IK input on IC 200 is pin 25, cap coupled (ac sig in only)
>and
>> >> >signal
>> >> >> >comes from RM pin 4. Also check IC203 for 9V as that drives Pin 6
>> >Ic200
>> >> >and
>> >> >> >that Q2H04/Q2H05 >>weird 2 transistor<< combo.
>> >> >> >
>> >> >> >Looking at the Block Diagram shows that IC200 video jungle is
>> buffered
>> >> by
>> >> >> >Q2h04 and IC204 is Gamma Correction IC, buffered by Q222.
>> >> >> >
>> >> >> >HTH, if not ask and I'll get more info to you, can't copy schem,
>too
>> >> big.
>> >> >> >
>> >> >> >Damon Brunger
>> >> >> >damon101@xxxxxxxxxxxxxx
>> >> >> >Telrad Electronic Services
>> >> >> >Ft Wayne, IN 46815
>> >> >> >
>> >> >> >----- Original Message -----
>> >> >> >From: "LeRoy Westlund" <llw@xxxxxxxxxx>
>> >> >> >To: <techassist@xxxxxxxxxxxxx>
>> >> >> >Sent: Sunday, January 12, 2003 4:32 AM
>> >> >> >Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to blue
>> CRT
>> >> >> >
>> >> >> >
>> >> >> >>
>> >> >> >> Yes, Yvon. I tried that, and the blue CRT is OK.
>> >> >> >> I think the jungle IC is bad,...but, just like to scope the RGB
>> >> >outputs,
>> >> >> >> before ordering a new one.
>> >> >> >>
>> >> >> >> Thanks,
>> >> >> >> LLW
>> >> >> >>
>> >> >> >> LeRoy Westlund
>> >> >> >> Westlund TV & Electronics " Walk tall,...Walk straight
>> >> >> >> 93 North Main and look the
>world
>> >> >> >> Centerfield, UT 84622-0087 right in the eye "
>> >> >> >> Ph./Fax 435-528-3822
>> >> >> >> mailto:LLW@xxxxxxxxxx
>> >> >> >>
>> >> >> >> -----Original Message-----
>> >> >> >> From: Yvon Roy <atlantek@xxxxxxxxxxx>
>> >> >> >> To: techassist@xxxxxxxxxxxxx <techassist@xxxxxxxxxxxxx>
>> >> >> >> Date: Saturday, January 11, 2003 1:20 PM
>> >> >> >> Subject: [TechAssist] Re: Mitsubishi PTV VS45501A No video to
>blue
>> >CRT
>> >> >> >>
>> >> >> >>
>> >> >> >> >
>> >> >> >> >Not familiar with this model but just a tought for checking if
>the
>> >> CRT
>> >> >> is
>> >> >> >> >good, try to connect the video of the green or red to the blue
>to
>> >see
>> >> >it
>> >> >> >> the
>> >> >> >> >blue will work ok. Or switch the crt board.
>> >> >> >> >
>> >> >> >> >Yvon Roy
>> >> >> >> >
>> >> >> >> >Atlantek TV Service
>> >> >> >> >1295 Miramichi Ave
>> >> >> >> >Bathurst, NB
>> >> >> >> >E2A 1Y1
>> >> >> >> >Tel: 506-545-7805
>> >> >> >> >Fax: 506-546-2171
>> >> >> >> >
>> >> >> >> >----- Original Message -----
>> >> >> >> >From: "LeRoy Westlund" <llw@xxxxxxxxxx>
>> >> >> >> >To: "TechAssist" <techassist@xxxxxxxxxxxxx>
>> >> >> >> >Sent: Saturday, January 11, 2003 3:37 PM
>> >> >> >> >Subject: [TechAssist] Mitsubishi PTV VS45501A No video to blue
>CRT
>> >> >> >> >
>> >> >> >> >
>> >> >> >> >>
>> >> >> >> >> Hi Members,
>> >> >> >> >> I am trying to trace the video back from the blue CRT board,
>to
>> >see
>> >> >> >where
>> >> >> >> >I
>> >> >> >> >> am losing it. I have good video driving the Red, and Green
>> tubes.
>> >> >> >> >> I Have NO video on SG pin 1.
>> >> >> >> >> Also, no video on RM pin 3.
>> >> >> >> >> Also, nothing driving Q222.
>> >> >> >> >> From that point, I am lost with out a schematic.
>> >> >> >> >> I am asumming that the video driver IC is IC200, but, not
>sure.
>> >> >> >> >> If IC200 is correct, which pins are the RGB outputs, and what
>is
>> >> the
>> >> >> >part
>> >> >> >> >> number for IC200 ? Also, is there anything in between IC200,
>and
>> >> >Q222,
>> >> >> >> >that
>> >> >> >> >> could block my video, that I need to check ?
>> >> >> >> >>
>> >> >> >> >> Thanks for any help,
>> >> >> >> >> LLW
>> >> >> >> >>
>> >> >> >> >> LeRoy Westlund
>> >> >> >> >> Westlund TV & Electronics " Walk tall,...Walk straight
>> >> >> >> >> 93 North Main and look the
>> >world
>> >> >> >> >> Centerfield, UT 84622-0087 right in the eye "
>> >> >> >> >> Ph./Fax 435-528-3822
>> >> >> >> >> mailto:LLW@xxxxxxxxxx
>> >> >> >> >>
>> >> >> >> >>
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