我用jlink v8连接不上TQ2440，不知道什么原因？

我是用的jlink V8，转接板就是用的jtag上的那个接口。打开jlink commander显示信息为：
SEGGER J-Link Commander V4.08i ('?' for help)
Compiled Jul 31 2009 18:24:44
DLL version V4.08i, compiled Jul 31 2009 18:23:57
Firmware: J-Link ARM V8 compiled Dec  1 2009 11:42:48
Hardware: V8.00
S/N : 20100214
Feature(s) : RDI,FlashDL,FlashBP,JFlash,GDBFull
VTarget = 3.313V
Info: TotalIRLen = ?, IRPrint = 0x..FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF1

WARNING: No matching core found. Selecting default core (ARM7).
Info: TotalIRLen = ?, IRPrint = 0x..FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF1

****** Error: Could not find supported CPU core on JTAG chain
No devices found on JTAG chain. Trying to find device on SWD.

WARNING: No matching core found. Selecting default core (Cortex-M3).

****** Error: Parity error (Data = 0xFFFFFFFF, ReceivedParity = 1)

No device found on SWD.
Cortex-M3 identified.
JTAG speed: 5 kHz


之前突然连上了，之后有不行了
怎么解决，麻烦各位指点指点

灯还亮么？

绿灯一直亮起的

我碰到过和你一样的问题，解决方法是——关掉开发板电源，把转接板上3.3V IN和3.3V OUT用跳线帽短接，另外一边的跳线帽拔掉，重开电源再试一下，应该就好了。

哦 我没有用转接板   是用的天嵌jtag带的jlink接口