Disassembly:

The cover is held on by 2 philips screws on the left and right sides as well as two on the back. It is also held on by 2 security screws on the upper-back, shown in the picture below. These can be removed by a good pair of Vice-grips; the needle nose style seems to work best. The second option for removing the security screws is to take a hack saw or Dremel tool and carefully cut a slot into the screw head and then use a flat head screw driver to remove them. The third option is to drill out the security screws with a very small diameter drill bit. If you choose this method, be sure to cover the top of the receiver to prevent metal shavings from falling through the slots.

Once all screws are out, push the lid horizontally toward the back of the unit and lift it off. The plastic front panel and circuit board therein simply snap on/off via plastic tabs. Disconnect the flat cable by pulling from the sides, NOT the cable itself. The cable is difficult to remove — pliers are recommended. Pull firmly on edges of the cable so as not to bend the pins when the cable slides off the board.

It is also possible to remove the front cover without removing the case (or security screws) by unlatching the front cover tabs. The approximate location of the lower left tab is shown in the picture below, the tab extends and latches on the inside of the case. To remove the front cover insert a small, flat object (such as a 0.035-inch feeler gauge or thin Popsicle stick) in the top air vents near the front panel and push down on the bottom tabs just enough to unhook them. First one side and then the other. Next pull the front cover forward a little, push up slightly, and then pull forward to remove. To reassemble, push the top tabs in first then the bottom tabs. You will need to remove the daughter card from the front panel. This technique doesn’t work as well on model 2000 or older units because the tabs are much less flexible and can break off (the tabs can be epoxied back on).

Identification of the electronics:

There are at least 3 different styles of 4000 front panel, each with a slightly different circuit board. If your 4000 has a small oval-shaped window where the power LED is located, you probably have style A. If your 4000 has a large, slightly curved window covering the entire upper center of the front face, you have style B. It is rumored that all JVC receivers are style B. The third style is something of a mystery. Many people seem to have it and the required parts are the same, however the silk-screened part designations (U1, C1, etc.) are at least partially different. If one of the component designations listed below doesn’t completely match up with vacant spaces on your board, you have style C. Style C owners will have to compare the openings on their circuit board with the circuit diagram at the bottom of the page to determine appropriate placement. Rest assured, however, that the parts listed below are necessary in all cases, only the designation changes.For 2000 Deluxe receivers, use the upper mounting location to match the pins of the DigiKey IR receiver.

These are the components of the front panel daughterboard. No modifications need to be made to the main board.

Style A:
U1………..Integrated IR receiver module
Q1………..PN2907 transistor
C1………..100uf 16V electrolytic capacitor
R1………..22k ohm resistor
R2………..10 ohm resistor
R3………..10k ohm resistor
R4………..47k ohm resistor
Style B: (HTS-branded units, possibly others)
U1………..Integrated IR receiver module
Q4………..PN2907 transistor
C1………..100uf 16V electrolytic capacitor
R7………..10k-ohm resistor
R8………..22k-ohm resistor
R9………..47k-ohm resistor
R10……….10 ohm resistor

Click here for pictures of the HTS 3200 circuit board

Click here for pictures of an ExpressVu 4500 circuit board

Click here for a picture of the HTS 4500 circuit board (unpopulated)
Some Philips Magnavox 4000 series Echostar receiver:
C3………..100uF- Slot C3 on the board
R11………10 ohm
R7………..47k ohm
R8………..22k ohm
Q3………..2N2907
R9………..10k ohm

There is a 10k-ohm resistor that is installed on some boards and not on others. This is R3 on style A boards. If your board doesn’t have this resistor, you will need to install one.Resistor identification by Color Bands:

Resistor Tolerance (fourth band):None +/- 20%
Silver: +/- 10%
Gold: +/- 5% (standard, 5% or better recommended for upfit)
Red: +/- 2%

Installing the components:

U1 is a 3 pin device with an IR phototransistor and op-amp / comparator circuit hooked together to deliver a TTL waveform representation of the infrared light pulses striking the phototransistor. (If you care.) The 3 pins are Vcc (+5V), Gnd, and Vout (Data Out). Echostar uses a U1 that has Vcc in the middle and Gnd on the left (looking from the front of the board). Make sure you know the pinout of your U1 before installing it; you may have to do a little creative lead-bending. The signals should be the same; only the placement may differ. On the circuit board, Vcc is the trace that connects to the 10 ohm resistor. Gnd connects directly to the ground plane. Vout goes to the 47k resistor. Generally, IR receiver modules have some sort of a metal shielding surrounding them. Be cautioned, removing the shielding can greatly reduce the IR receiver range. To locate the ground pin, measure resistance between the metal box and the 3 pins; the Gnd pin will read will read 0 ohms resistance. Once you’ve found Gnd, you can safely distinguish the Vcc and Vout pins by trial-and-error.

The IR receiver from Allcorp has a 5-foot cable leading from the module (shown in the photo above) to a stereo mini-plug. Cut and strip the cable near the mini-plug connector to expose the 3 wires inside. The red wire is Vout, the black (or sometimes white) wire is Vcc, and the bare/shielding wire is Gnd. (If you leave the mini-plug attached, Vcc goes to the tip of the mini-plug, Vout goes to the center band, and Gnd goes to the bottom band nearest the cable.)The IR receiver from Jameco has Vcc on the left, Gnd in the center, and Vout on the right, when looked at from the front, turned so that the leads are on the upper edge. Vcc and Gnd will have to be switched by doing a little bending.
The IR receiver from DigiKey has the pins in the proper orientation with Gnd on the left, Vcc in the middle, and Vout on the right. You will need to check that the eye lines up with the hole on the front cover; you may need to bend the receiver a little bit.

Outlines of the components are silk-screened on the top of the circuit board, so the orientation of sensitive components like the capacitor and the transistor shouldn’t be a problem. The board has holes and solder for the necessary components, all you need to add is the parts. Capacitor C1 is mounted with the negative strip facing upwards on board Style A; the negative pin goes to ground. Be sure to mount the capacitor close against the board; otherwise it will be too tall and push against the front cover after reassembly.

The board is wave-soldered, so you can either heat the existing solder and push leads through one at a time (easiest) or remove the solder from the holes and re-solder the components. There are 2 mounting locations for U1, with the one on the left being the primary location and the one on the right being the alternate. The Style A board, with all components installed, is shown below.

Once you’ve installed the components and checked thoroughly for shorts, opens, lost contact lenses, etc., plug the front panel into the motherboard, insert your smart card, hook up the antenna and TV out wiring, make sure the back of the front panel board isn’t shorting against the metal frame, and power up. If all goes well, you are ready to activate the IR circuit (4000 and lower models only).

When snapping the circuit board back into the front panel, make sure the lens or window on the IR receiver module lines up properly with the cone-shaped window (style B) or the hole above the power LED (style A) provided for it. A mis-aligned receiver can cause diminished range or no response at all. Also make sure you clipped all leads off roughly to the length of those of the preexisting components. Leads too long can short against the metal frame after reassembly.

Test the remote control before reassembling the receiver.

Circuit Diagrams Notes:

In case there is yet another unknown board style out there, here are 2 representations of the circuit you are rebuilding. The component designations below (R1, C1, etc.) are for Style A boards. If you have a different style of board, you will need to determine the appropriate component designations.

Gnd _____/-_____
| _____________________ | IR | U1
/ |Vout_Vcc_Gnd|
10k/ ___|B__PN2907 R1 | R4 | | |_______
R3 _____/ ____///____|__///________| | |
| C| |E | 22k 47k | |
| | | | R2 | + - |
|___| |_____|_________________________///____|—-|(—–|
| | 10 100uF |
_________Out +5v C1 Gnd
(Cable pin#) (10) (2) (1)

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